Perfectly... well as well as anything without RTC plays GBA games (which is almost all of them give or take a handful of patches). Certainly no slowdowns and most issues that can be fixed (basically everything but the likes of the TV tuner, the unlicensed organiser, gameshark/codebreaker/action replay dumps and whatever else like that) is fixed with a simple patch or two. The only true absentee at this point is pokemon emerald.
Working on the device mentioned. Assuming it is a straight up hardware clone there is no reason why it should not -- it works on the GB player, it works on the K101 from what I recall. If the dev team has gone cowboy and emulates the hardware at some level or has every game programmed into the thing and adjusts the hardware accordingly then all bets are off but it is still not a bad bet.
