I am using the Plugable 60W USB 2.0 hub and it does work fairly well as long as you know its quirks.
Quick guide to follow:
Stated before but 3 sticks is the max. I don't care what speed you run them at, stock or over clocked 3 is the max.
Must run on ports 1,3,5 or 2,4,6 and a fan can go into slot 7 but it draws from port 5,6,7 combo. I run my fans with a separate supply.
Max frequency you can run the sticks at and not have it go zombie or get a USB error is 237.50Mhz and that may be pushing it as each hub may differ slightly (225 Mhz might be more stable for you).
If you lose power for any reason you must manually push the power button to turn it back on. Use a small UPS to keep it alive if you plan to run unattended.
Set voltage to the lowest setting .69 - .70 across the ASIC voltage and you shouldn't get any hardware errors
237.50Mhz should get you between 72Ghs - 76Ghs
Supplied power brick is reliable and only gets warm not hot
Over all price point is great
I ran 3 sticks at 250Mhz for a while but eventually one stick goes zombie or you get a USB error. Might be 30 minutes might be 6 hours but it happens every time at that frequency. You also have to up the ASIC voltage to .70-.71 to get no hardware errors.
If you are good with all of that I would recommend getting them.
How to measure the ASIC voltage see here
https://bitcointalk.org/index.php?topic=1764803.msg17678108#msg17678108Thanks for this. Have the same hub.
Question: Any luck chaining them together? I have 4 2pac's and have been trying to get the 4th to keep running but no matter what powered hub I try it runs for a few hours then stops.
I ask because I am using a RPi W with one USB port.