I'm a sucker for being able to play as the bad guy in video games, like Meta Knightmare and Dededetour in the Kirby series. The cool factor of being able to play as Metal Sonic wears off once you realize you're playing him in Sonic 4 Episode 1 levels, and he's functionally identical to Sonic. If you want to have fun playing as Metal Sonic, download a fan hack for a better game, or play SADX and SA2B.