jxd seems to be one of those companies that just says screw it, as is evident with their s7100, it runs android 2, and has a a9 processor, which is powerful enough to emulate n64 games. The reason why the s7100 does well and ppl embrace it, is cuz it has physical controls, picture a kindle fire(7in screen) in your hands and on the sides you have a playstation controller, which they blatently ripoff and just don't give a f...
this was last year when my friend was looking around and we did research, he says he likes his, there is a newer more powerful one out but it has a 5in screen (i don't know the difference haven't researched)
then the ones you've seen the full 9in ipad copies, no idea on these... as the reason why the jxd company actually did well was they merged a 7in screen android device that could play roms with a surprisingly good controller built in.