Heavy is by far my favorite class. Nothing new I didn't really know in here, but the jump and spin around corners tactic is mandatory for a quick surprise.

I'd also recommend having an engineer build a Dispenser next to a choke point and you stand right on top of it. It'll heal you slowly and keep your guns spinning. You can literally fire the entire time, you won't run out of ammo. If they start firing on the dispenser/or you, you can use it for cover, or if you have a medic stand in front of it and block it to keep your gun spinning.