According to EGM, the PS2 version of Sonic Heroes runs at about half the frame rate of the other two, takes at least 4x longer to load, and somehow or another even SOUNDS worse than the others. LOL.
JevilKnevil: The previous two Sonics were disappointments because SEGA fanpeople simply CANNOT comprehend the theory of "Updated Gameplay", unless it doesn't happen with other companies. (read: They want another Sonic game that'd basically play exactly like the Genesis ones, and yet they bashed Mario Sunshine and Zelda TWW, among other games, for not really changing the gameplay of their predecessors)
Sonic Adventure and Sonic Adventure 2 of course aren't flawless by any means, but they aren't as horrible as everyone seems to think they are. >_>