So basically the difference between this and the retroUSB AVS linked above is a) lower output resolution (but I assume everything's being upscaled from the original NES output anyways) and b) better case/connector materials? If they both have FPGAs they presumably perform the same otherwise, right? (you can probably tell I don't know much about this stuff)
It's not using the same core to run it, so there could be minor differences between the two in how well it runs games, but for all intents and purposes, it'll probably run games with no noticeable difference for a majority of the the people using it.