[quote name='looploop']So I just picked up an actual Sega CD recently... Would I be better or playing this in the original format or getting the XBLA port? I already know it'd be cheaper going with the latter.[/QUOTE]
The XBLA game has tons of improvements, including proper widescreen support, visual filter, US and Japanese soundtracks, the ability to unlock Tails as a playable character, the option of using the Sonic 2 spindash, and Achievements. Also the music loops properly and load times are quicker. Come on now, you really have to ask?