No, Sonic's terrible. He's fast, but it means nothing if his attacks are just average- he's still easy to counter, his moves have a good amount of lag, and he's got terrible hitboxes. Fast ground speed only pressures the opponent to think faster, but once they're in the air you lose that advantage as well, and it's not much of a big one since you have to think faster too. Bad damage, bad knockback, decent lag, bad damage taking, and good ground speed. Just a poor character overall. Plus, his specials are neasr unusable, as they actually LIMIT your approach options.
He's not the worst character, Captain Falcon has absolute failure as priority and mediocre moves at best, but then again he's the bottom of the bottom for a reason. He's far from a good one though.
Playing that many characters can't be that good for you, as fully learning a character takes a lot of time for most people. I wont believe anyone here's good or bad until I play them in a game of Smash that isn't made out of lag.