I'd just like to interject for a moment. Long respawn times are fine, but fuck arena.
Team Fortress 2 uses a class based system, giving different classes different merits for the purpose of balance in prolonged gameplay.
Engineer for example is designed for remote camping; creating a sentry and running away or hiding. In the objective-based gamemodes, Engineers can keep a sentry alive after dieing multiple times, providing constant defense support at the cost of being overall a shit class. In Arena mode, it's all over when you die, meaning Engineers have to build a sentry, run away and somehow stay alive with a low short-range DPS and completely useless long-range weapons.
Heavy, with his retarded DPS, self-healing and bullshit melee range, has absolutely nothing to fear other than Spies and Snipers.
Spy, although being effective in most scenarios, becomes blatantly obvious the very moment he kills anyone. Once people know there's a Spy around, they're gonna rape him within seconds, whereas in objective modes one can switch to Spy, get about ten kills in the confusion, then switch to any other class and continue pushing or defending.
Pyro is OP in 1-on-1 against every class other than Heavy, and without the constant team distribution that the objective modes offer, it's gonna become really hard to kill a Pyro when there's only 4 players left. If however one of them is a Sniper with decent positioning, all it has to do aim at the head and click for an insta-kill.
tl;dr other than broken classes like Pyro, Spy and Engie, Arena is basically a game of rock-paper-scissors with hats.
