When a game suffers from so many camera and collision detection issues like Sonic Heroes does, it basically ruins all of the good points. It had a lot of potential, but none of that was fully realized thanks to the the utter shoddiness of the production.
I mean this is SONIC THE HEDGEHOG we're talking about. Sonic was Mario's one true rival back in the day, and Sega's flagship character. Like Mario, Sonic should have represented a superior level of quality and polish in each new iteration. Mario's 3D adventures were continually honed from Mario 64 through Sunshine and culminated in the brilliant Galaxy. Sonic had a hit in Adventure 1+2, but then suffered with Heroes' shoddy production values and culminated in the horrifyingly broken Sonic '06. Let's not even get into what a poor decision Shadow the Hedgehog was.
If you enjoy crappy games, then fine; a lot of people play and enjoy crappy games. But please don't think for a second that Sonic Team has actually been doing a good job with the series. They've been slowly and steadily running it into the ground since Sonic Adventure 2. The only saving graces have been the DIMPS developed Advance and Rush games.