So you have to snake cable through your case to use it... seems to have no sockets on the PCI bracket there... and it doesn't even run off the abundant arrangement of spare SATA and molex connectors in the average computer case?
The only way they could make it any less convenient would be if it doesn't turn on until you punch yourself in the nuts.
It doesn't need two 5.25in "half-height" bays - it needs a full-height bay. Many cases have non-removable integrated guides between 5.25in bays and the solid sides of this amplifier is going to prevent it from fitting in those. http://en.wikipedia.org/wiki/Drive_bay
Honestly I like the look of having the meters on there in an inverted color scheme compared to the meters you would find on a 80's cassette deck. If done right I think this would look really kick ass on a case. I understand why they are doing a separate power supply... trying to isolate the power source from the PSU that does HDD, SDD, DVD/CD, Mobo, Graphics Cards, Sound Cards and USB ports. But it still seems kind of stupid, rather just get an external one. I see why they would not have a back plate extension ports and instead went with a bracket with a hole. Even though it doesn't look as nice alot of audiophiles really like using their own cables, and adding and extension like that would add problem areas to the line. Though honestly, I don't think an audiophile would buy this...