is the gameboy advance port of Sonic really that bad; if it isn't i'll be pretty tempted to get one for myself.
It's truly horrible, the physic engine has been completely redone and due to this there are many MANY glitches. Seriously it's one of the worst ports/conversions ever.
Due to the size of the GBA screen, you can't see that far into the distence, the sound quality is pretty poor, there is popup, you can still get hurt whilst charging the spindash and really, it's just not very good. Shadow the Hedgehog is better then Sonic 1 on the GBA.
You should try out the first Sonic Advance if you want a Sonic fix though, it's the best of the advance series if you ask me.