As far as the whole character balance thing, the way I see it:
Sonic is the master of speed and agility. His superior speed allows him to pursue and flee from opponents, and his thok ability makes him extremely unpredictable in the middle of a ring-fight. The top speed comes in handy, but unpredictability is what truly makes Sonic a powerful character in match and ctf, since it more easily prevents other players from hitting the user.
Knuckles has the obvious advantage of an increased fire rate, which grants Knuckles superior firepower and allows him some room for error when it comes to weapons with a longer reload. Once again, Knuckles also has a slight unpredictability advantage, as his glide allows him to make sharp turns in the middle of combat. His ability to cross terrain and his speed are decidedly balanced, unlike Sonic, who is all speed and barely terrain maneuverability; this isn't necessarily better or worse, it just opens up different options.
The way Tails matches up against other characters is still a little bit debatable. His flight ability now sometimes gives him access to resources that other characters can't access, and it also gives him a different perspective on the field of battle, often improving the effectiveness of weapons like the bomb and rail rings. Part of me still feels that Tails falls short, however, since, unlike the other two characters, Tails is
incredibly predictable. The fact that he's typically airborne means that the z axis is not on the side of enemy rail snipers, but Tails also has almost no maneuverability while flying, meaning that usually Tails players will be either flying in a straight line or changing direction rather slowly. It would also be nice if team players could catch onto flying Tails players a little easier; no one uses it as a serious strategy in CTF, because it just takes too long to sync up the two players for flight across the map.
Summed up, Sonic = Quick Wit, Knuckles = Brute Force, Tails = Strategy(?), with Tails slightly limping as far as skill ceiling goes.
On topic!
Mystic's a dev and knows the game in and out, so naturally he's always been a tough opponent, good fun to play against. I just can't get over
this one match on I think FuriousFox's server; granted, it was Meadow Match and I was just spamming bounce rings like nothing else, but it still felt epic to top the scoreboard of a huge netgame, only to lose to Mystic himself. It's a screenshot I'll always cherish.
Armonte's pretty damn good too. I haven't been playing CTF and Match so much anymore, but I've run into a good handful of skilled players. I should play a little more often so I can find more people to add onto the list.