I like to think I do a pretty good job as a medic, though it can be a pain to heal the guy you want when they're all running around in front of you. I gotta admit, though, that I don't really like being stuck as a medic because no one else is playing as one. I'm with Gamercat in that I'd rather play as Heavy, or even Scout or Pyro depending on the situation. Maybe even Sniper, if I'm used to the map.
Medic is credit to team! I like to think I do a pretty good job as a medic, though it can be a pain