This seems like a very reasonable deal? Is there some hidden catch? Also, can anyone explain to me the $500 difference between buying first batch and second? It it simply because they think the difficulty will rise substantially following second batch? Just wondering. Thanks. Anyone have suggestions on hosting options?

Yes of course there is a hidden catch...I was caught of guard as well by the price (lower than the original L3 at twice the hash power?). Its obvious bitmain is prepping to dump these on the market. Scrypt hash power will tripple in the next 2-3 months.
Don't forget that they are also taking advantage of the recent price hikes to make it look like this is a super deal. Dont think that this LTC price will last forever (though I hope I'm wrong).
The shipping date for April has already been sold out! don't understand why they cant just ship all of them out at the same time

does anyone know what any other PSU I can use on the ant miner L3+ besides the APW3+-12-1600W? ..
if the entire unit can run at 800w that means u can use 1 dps-1200 server psu and 1 breakout board to run the entire miner. there are 4 hashing boards so if the total power draw is 800 that means each pci cable will handle less than 200w if you consider that the controller is using some of that 800w to power itself and the 2 fans. If those numbers are correct you can run the entire miner with only 5 pci-e cables but only if they are 16awg cables. most pc power supplies use 18awg which in that case you would need a total of 9 to power this miner. all of my psu's u are server psu's or have cabled that i swapped with the stock psu cables so i dont run anything less than 16awg cables. if you want to be careful (probably the best thing to do) you can use 2 16awg cables per hashing board and 1 for the controller. either way at 800w the entire miner can run from one server psu based on the model i listed above. you dont need to use bitmains psu which is more expensive and is less reliable. that and it requires 220v to run their current miners at full speed.
i got 4 of the l3+'s. i cant believe that ebay listing wanted $4800 for one of these miners...more than double the cost from the manufacturer directly. for once bitmain didnt screw us on price. they were completely reasonable and im thankful for that. the $450 difference is based on them being shipped by the 15th of april vs them being shipped by may 5th. i went with the april batch because i dont like my money sitting in limbo any longer than it has to.
to the guy asking about temps and noise...im feeling like that isnt the case honestly. it has the same design as the s9 and has 2 fans just like the s9 but u have to remember the s9 uses the better part of double the power the l3+ uses anddddd the l3+ has 4 boards instead of just 3 like the s9 so less power goes through the boards....less heat....more surface area for the heat to spread out to which in turn means more surface area for the air to come in contact with....all that seems to equal less air is needed which in turn means a quieter miner. this is just me guessing though and i dont have my order yet but based on the info im seeing it seems like that is the case. if not thats fine too since these wont be runnig in my house anyway.
Let us know how it works out for you. The current L3's that I have run 4 boards also, but heat is a factor at only 400 watts. Many people have to turn the fans up on the L3's to ensure there is enough air flow for the interior boards. So that is why Bitmain shoved a second fan on there and they are going to pump up the volume in more ways than one.
I suspect you are going to end up with a miner on the same playing field of the S9. So we will all be looking forward to the reports on how these run for you and the sound levels from these.