A slight worries ...

It is excellent for providing power:
6 2.5 "hard drive USB3 (3 * 5400T / min and 3 * 7200 / min) + 1 HDD 3.5" USB3 (with its own power supply) and not flinch! It must be said that the 12V adapter / 4A can provide 48W. The manufacturer recommends all the same not exceed 7A (of 5V), which still leaves power 35W. Writing on 6 discs fed by the HUB, I get about 22W, so there's margin :)

As against a large, due to performance:
Hard Drive Hard Live my PC connected USB3: 110MB / s
Hard Drive Hard Live USB2 connected my PC: 25MB / s

Hard disk on the Hub connected USB3: 33MB / s
HDD USB2 Hub connected: 25MB / s

So there seems to be a mismatch. Yet I have tested with two different external drives USB3 and they have no worries live!
Asus G74SX + Fresco Logic USB3 FL1xxx
Maybe the cable (supplied) from the HUB and PC (type B) Is faulty and causes reduced flow communication? Or is it that the hub is down?

I hope to contact the manufacturer to clarify what worries speed, which would make this perfect Hub!