Hi, I received the Apollo today and the build quality is amazing.  The FedEx guy advised me to tell you to NEVER pu the contents and value on the label on the outside like that.  He said it was the talk of the local office with everyone commenting on bad of an idea it was.  Please don't do that - I mean it would just take folding the paper one more time to hide it.

There are several things at play here that make this worth investing in. 
First, running a node can help the Bitcoin network - even if only a little bit. 
Second, the chance to run a quiet system that mines like this one is somewhat unusual. 
I think the quiet mining and good hardware is what explains the success of the R606's as well. 

At current Bitcoin prices, it is tough to say this would ever make a profit but most of us believe strongly in BTC and have for years. 
This and other small miners (like the R606's) retroactively become profitable as BTC goes up. 
I personally expect BTC to be 100K or more by August which would make this profitable. (Just my opinion.)

I just got in after seeing your post - thank you!  I was sad to miss the original chance on this so I'm happy I got in now.
Cannot wait to get this and setup it up.

I would be interested in three or four of these once you have them ready!  I have been looking for a replacement to the R606's and you do make great hardware!
I would also probably design and 3d print some kind or bracket or case if they came without one.  I've done some carbon fiber style cases that can take a bit of heat.  If I did design something I would release it for everyone to use.

I tried a RPi2 and it ran okay for one R606 but as soon as I added another it had problems.  A lot of errors and it eventually crashed.  I think the problem is the USB - it is just not great the the RPi1 and 2.
I switched to a RPi-Z (got it for $5 from Micro Center) and it has been running well for over a year with five R606's.  
It does occasionally go belly up for some reason but a simple reboot gets it going again.

When you have a chance, can you fix my login on the list (number 2)?  In case I win I wanted to be sure you can find me 
My login name here is Lrowland21093 (the first letter is an "L").  Thank you! 

With the new build downloaded on 5/28 the speed has dropped to 580MHz (with a total hash rate of about 1.9TH for the three R606).  I'm going back to the earlier version since it works so much better on the Pi Zero.  Probably if I ran on a full power PC with Windows or Linux the newer build would work better.

My data point is 700, 705, and 710 MHz on three R606s using Raspi Zero at voltage level 7 giving total 2.6TH on average after about 5 days running on build a62385f. 
Still pleasantly shocked that Pi Zero can handle this!

I'm going to download the latest build tonight and start a new run to see the difference.

When running on a Win10 machine I do get about 100Gh higher but the second I use the machine for anything else it drops back by quite a bit.  I like running them off the Raspberry even if it is a little slower.  The Pi's work well and use less power.  With the great GS hub it makes everything very streamlined.  I did just pickup a Pi "HAT" that has a hardwired network connection that may help (though I think it is still on the USB bus so it may not make any difference).  The HAT is called a "MakerSpot 5-Port Stackable USB Docking Hub" and has USB and a network connection.  There are lots of similar Pi add-ons that might help like this one with USB and network connections.  Of course the Pi Zero's are so cheap it was worth the experiment ($5 if you happen to be near a Micro Center in the US).

Anyway, a few hundred Gh for such a lower amount of power seems worth it to me.  With that said I do get the desire to squeeze as many hash as possible out of these little boxes!

As an experiment I setup a Raspberry Pi Zero W with the GS hub and three R606's.
After a full day the hash rate on all three match the Pi 3b+ speed which is 900Gh.  These are also the numbers I saw on a Windows 10 PC.
Next is the TinkerBoard but it will probably just be the same. 

I think the only two constraints (as others have mentioned) are the USB traffic and the possibly the network connection.
The fact that it worked at all with the Pi Zero was surprising let alone at the same speed.

I tried to run the Pi off the R606's USB and it would not boot.  Now it is running off one of the ports on the Gekko USB hub and it working well.  Mine has a 7" Waveshare LCD powering from the Pi so I assumed the power troubles were because of that.

Just as an experiment I am going to try running the miner on a Pi Z - though I don't really expect it to work.  It will be cool if it does since you can get them for $5 from Micro Center right now in the US.  Somewhere I have a Asus Tinkerboard too that I may try.  Either way I'll post results in case any one is interested.

One more data point - I have three R606 from 419.  One of them was giving me the blinking lights and would not mine higher than about 200GH.
I worked with Nick from 419 and after compiling the latest cgminer on a RPi all three are hashing 800-900 each now.
This is using a Gekko USB hub and one of the HP DPS-1200FB power supplies.  
Again it is on a RPi.  I have tried mining with cksolo, kano, and slush and ASICBoost works on all at the same 900GH on all.

The one miner that is blinking is apparently #1 off the "assembly line" according to Nick (it does not have a notch on the case for the USB connection).
While it is still blinking, it is running nicely now.

Using a laser thermometer, the temperature on all three miners is about the same - about 100F.

These are great little machines - thank you sidehack for making them and vh for updating the cgminer!!

I am not sure if this is helpful but it does work well for me.  There is a fairly easy way to manage times where there is a bit of excessive heat.  Put the Raspberry controller's power on a WiFi enable "smart switch" and then connect the switch to IFTTT (If-This-Then-That) running on a tablet or phone.  The write two scripts that turn off and then on the power to the controller when the temperature gets to a certain point (you can use Weather.com or you can buy a sensor for the room where the miner is). 
The benefit of this is you are not cutting power on and off the miner, just the controller.  The Wifi plugs are really cheap now too and IFTTT is a free app.

My miners go off when the outside temp goes above 90 and then back on when it drops below 85.  This means they turn off during the hottest part of the day (electricity is in demand then anyway).  Here is a good article on IFTTT: https://www.cnet.com/topics/smart-home/best-smart-home-devices/best-ifttt-compatible-gadgets/
and here are some good prices on compatible smart plugs:  https://www.amazon.com/s/url=search-alias%3Daps&field-keywords=wifi+smart+plug+ifttt

I had to join in to say Nick/Blokforge's customer service is the best I have seen in the Bitcoin community!
To go to bat for us like that with Canaan and then offer additional discounts to those who got early 821s is really great service.

Hopefully the difficulty won't rise too fast with all these new 821s and 841s coming online!  

Good information from Canaan - thank you for contacting them (just gave you one of my few merit points I have to give ).  I just changed the temp target to 80 - the fan seems to be still tolerable and keeping the steady chip temp at 70 with this setting.
I agree that when they have a working undervolt that could be a better options.

As promised, here is a screenshot showing the new settings.  it is really working well now and is as quiet as the 741s.   

https://i.imgur.com/4cF1ZTO.jpg

Tried changing the frequency and so far, it doesn't work well with any setting other than 650.  I tried 600, 625. 636, and 675.  For each one I lt it try to hash for about 30 minutes and each time the overall hash rate barely got above 2TH.  Setting it back to 650 and it went back to about 11TH immediately.

My guess is that the chips on the 821 are pretty much set to only work right at the 650 frequency.  Of course, I could be doing something wrong so maybe someone else will have success.

So it looks like one setting that does work well is the "--avalon8-voltage-level".  I set mine to -1 (range is supposed to be -15 to +15) and it is running cooler by 10 degrees and the fan is staying around 65-70% with a hash rate about 9-10TH. (Plus, it is much quieter now.)  I also changed the target temp to 90 which makes the fan run more like the 741s.  I'll let it run overnight and take a screenshot tomorrow.  It will be interesting to see if there are power use differences when HagssFin retests.

Here is what I put in More Options:  "--avalon8-voltage-level-offset -2 --avalon8-temp 90 --avalon8-voltage-level -1"

So far it is running around 86% fan speed (it was 100% before) with chip temp at 67 C.  The hash rate is staying between 10.5 -10.8TH - with the offset of 0, it was 11.2-11.5TH.
Overall it is much quieter but I will probably keep working with it tomorrow to see that new fan ramping point can be adjusted and may the shutdown temp set to the standard 99.

Screenshot after one hour with offset of -2  (sorry I don't have a before screenshot - if I have time I'll try to set it back tomorrow and let it run for an hour to directly compare):
https://i.imgur.com/WRCu5Gf.jpg

I posted a note about the voltage offset in the Avalon 8 official specs thread (https://bitcointalk.org/index.php?topic=2616205.msg30730555#new).
It looks like the values for voltage offset enter on the CGMiner Configuration page are being ignored and the offset and some other settings are getting applied to the command line of the cgminer.  
Try entering a value there other than zero and look in Processes - at the bottom of the list you should see the cgminer command line and it always has offset of 0 hardcoded.  It looks like we can override if we use "More Options" with "--avalon8-voltage-level-offset -2" (figured that out by taking akadamson suggestion and then finding the developer documentation for cgminer on Canaan's github.

For those who don't know or are new to this, the command line options can be found here (just look for the avalon7 options and maybe the options for avalon8 will be similar):  https://github.com/Canaan-Creative/cgminer/blob/master/README

So far it is running around 80% fan speed (it was 100% before) with chip temp at 67 C.  The hash rate is staying between 10.5 -10.8TH - with the offset of 0, it was 11.2-11.5TH.
Overall it is much quieter.

I don't have a way to test the power usage so if someone else does, it would be a good thing to test.

After setting up my A821 today, I made some interesting discoveries that I think explain what is going on with the voltage offset tests in HagssFin review and with what others found with the fan % and temp cutoff.  Several values are hard coded into the cgminer startup command and do not have some of the settings that are in the screen.  For example, the voltage offset is always set to 0 and even if you enter -2 in the miner configuration, it will not get passed to the cgminer startup.  The same holds true for the fan range (hard coded to 50-100) and the frequency.

You should be able to see this by going to the Processes screen and looking toward the bottom for the cgminer startup command.  You should be able to see what is hard coded and then entering things like voltage offset doesn't get entered here.

To get around this specifically for voltage offset, I put the following in "More Options" similar to what akadamson suggested:  --avalon8-voltage-level-offset -2

Here is a image of the Process showing te hard coded voltage offset as well as the override on more options - note I also had my offset int he CGMiner Config screen set to -2 but that did not do anything...
https://imgur.com/IhP3kSL

For those who don't know or are new to this, the command line options can be found here (just look for the avalon7 options and maybe the options for avalon8 will be similar):  https://github.com/Canaan-Creative/cgminer/blob/master/README