Yes, I've added more games. I've got the newer non-OGG version (I'm not sure that anything that hit retail was actually the OGG version).
Anyway, heated up the decal on the bottom with a hair dryer, peeled it back, threw away that worthless hidden screw and now this is an easy unit to take apart without doing any cosmetic damage.
I installed the 15 second adb drivers, plugged it in to my Win7 machine, let the computer crank on drivers for 20 minutes. Then you run a few simple command lines and you're in business.
After that it's a matter of dragging and dropping a rom and png for each game you want to add, and you have to make an entry in the gamelist text file. I basically have it "Kill everything that moves. A-Punch B-Kick C-Jump" and that's good enough for meta data.
Only hitch I've hit so far is it didn't like some of my file names. System was a brick until I started over and installed them in smaller batches. Not sure what was the culprit specifically, but it didn't like sor2, sor2, or tmnt as file names. Renamed to streetrage2, streetrage 3, and teenageninja and good to go.
Frankly, the default game list on this thing is reasonably curated, so I haven't felt the need to install much...