The unit does not supply 48v phantom power, even though the damned button on the front of the unit says "48v". It gives between 42 and 43 volts, which is probably fine for most microphones, but I'm not really confident about trusting a box that doesn't do what it says. I can only use it as a firewire D to A converter (a job which it does do well, to my ears).
Don't know how you measured this. All phantom supplies will only appear to be 48V if you measure with no load (ie, a very high impedance voltmeter). As soon as any current starts to flow the 6k8 feed resistors will produce a voltage drop. Less than 1mA current draw will produce a 6 volt drop, for example! Added to which, the phantom standard allows a 4 volt tolerance anyway -- the raw phantom supply can be anything from 44 to 52V quite legitimately.
I know, buyer beware, but readers like me do rely on reviews when it comes to researching which products to purchase.
Detailed technical assessments of products require trained and experienced technicians or engineers, with suitable test equipment and the ability to use it properly... and who can write coherently... and such people are pretty rare. So while I am sufficiently anal as to check the phantom power voltage, few others would.
What they would do, though, is plug some mics in and see if it all works as intended. And I presume in this case that it did. Indeed, I would be surprised if you noticed any issues with a phantom supply producing 43V unless you are working with extremely current-hungry mics or recording very loud sources at very close range.
I understand your concerns and share your frustration that some manufacturers cut corners in this way. But that is the nature of budget equipment, sadly, and 95% of the time they get away with it because, actually, it isn't that critical in most situations.
Technical Editor, Sound On Sound