Super Street Fighter II' Turbo/X:GMC looks better on 3DO via RGB mod than it does Dreamcast. Dreamcast is missing Gex too along with Need for Speed, Sailor Moon, Crash N Burn, Eye of Typhoon and a few other gems. On the other hand 3DO is missing the good stuff in DCs library.

Also, I'm not sure but I think the 3DO version may have sold more.
DC wasn't as popular as Saturn in Japan, this game came out near the end of the consoles lifespan. Plus 3DO enjoyed sales from three different regions, United States, Japan and Europe. One would think 3DO has the most popular straight up port of SSF2T&X.
Ultimately I prefer 3DO. Better d-pad, memory cache, and superior video output.
They're both great but the older system wins, IMO.
~Panasonic 3DO R.E.A.L. Interactive Multiplayer~
Aw yeah. 3DO is the real deal.