So I bought one of the "new" 16gb versions. Comparing it to my kid's older version, here's my thoughts in no particular order:
* Quality control seems a bit better, at least in regards to the outer casing and fitting.
* Given they're around the same price, if you want to just buy and forget, get the new model. It has about 3,000 roms, including most if not all of the NeoGeo collection. No repeats, and I didn't notice any "hacks".
* Same battery. Good enough for now, but I'll probably buy the gold "3030mah" one.
* USB transfer doesn't work out of the box. The USB icon comes up on the screen, but my PC doesn't see/connect.
* Motherboard is a different number but apart from a different version of the firmware, I can't detect any difference.
* Screen is bright, with no dead pixels.
* The white model has a small amount of light bleed around the LEDs. Doesn't bother me, but that doesn't happen with the black model.
Pretty happy with my purchase- probably the best "hack" handheld I've had since my Tapwave Zodiac. Thanks to LBL for the excellent videos. Now I just need to figure out 1) which custom image to put on this, and 2) How easy it is to use the RS97 stuff floating around on this site.