I capture uncompressed 720p from PS3 HDMI into a DeckLink Pro and it’s absolutely pin sharp, so I’d guess the weirdness with the Xbox capture is to do with its lack of a digital output and the signal conversions going on before it hits the card. Odd that the progressive capture looks interlaced and vice-versa, again it sounds like a problem internal to the Xbox image processing/output and nothing to do with the capture end of things.
The N3 capture could well have been dumped uncompressed over the network from a 360 dev kit. This’d give them a sharp, uncompressed, in-game capture (look at the aliasing on the ‘wings’) that would be 100% digital.