I have the Radioshack clone of this exact same keyboard (MD-992)
Basically put, it sucks compared to the Yamaha DX-7 and the microKORG. Even the Casio CTK-571 is better.
I NEED A MICROKORG. You loving know your stuff, man. I love the microKORG. I was considering the Korg micro X, though, seeing as you can plug keyboards into it. (that's why I find this keyboard useful, hehe, plug that into the micro X, plug the micro X into my computer via microphone or something and chapow, songs.)
But, I know, it does suck. But consider that I was suggested to have it for piano lessons in third grade (which I didn't finish anyways) it's pretty nice for $100, though. (at the time, at least.)
Oh and that was 5 years ago, so yeah. Now it's just home to a bunch of gross spider corpses :x I need to get it cleaned really badly.