I've got about a day and a half of time logged as a Pyro, alone, and I still have a hard time accurately reflecting everything that comes at me. It usually boils down to any server lag, or if the computer you're playing on is worth a damn, too. Nothing sucks more than seeing the Soldier firing animation, the recoil buck his launcher up, the exhaust plume starts, then the rocket freezes in midair before teleporting into your face. Alternatively, the rocket pauses for a moment after the firing animation before finally deciding to fly away - that'll botch my timing something fierce, too.