I checked one out at my local game shop. It seemed to play all the games fine, but I'm pretty sure you have to use the stock controllers that come with it. It also has no s-video output on it.
You'd be better off getting a Retro Duo for SNES/NES games and pick up an actual Genesis on the cheap. I stand by the Duo. It's a solid clone.
I personally do not trust Yobo's products, so IMO, its not worth it, mainly because they are cheaply made, graphics always seem slightly bleached, sounds are weird, and it always smell like melted plastic everytime I use it, or come near it, or even actually psychically touch it.