I personally was never into Sonic that much. I mean, I've played the Sonic games and still liked them, but I never really got into them. The big thing that deterred me from Sonic is that his older games (Genesis time period) gave Sonic ridiculously high inertia. That is, it was very hard to get Sonic to change directions or stop when precision platforming was needed. That is, when you compare them to the Mario games I practically grew up with. Also as a little child, I was a big fan of Nintendo Power, and back then, Sega was Nintendo's biggest rival and NP often made speaking of Sonic and the Sega franchise blasphemous. So, I followed that lead and stuck with Mario.
~I.S.~