Seriously guys, the Heavy is fine. The unlocks are good.
No knockback? What do you want that for? Heavy is my main class and I don't think I need that. What is going to knock you back? Sentries? You can already kill every Sentry in the game in seconds if the Engineer is not protecting it. Seriously, if a soldier is stupid enough to shoot the floor beneath you instead of your body so as to propel you backwards/into the air he is dead.
The Sandvich is amazing comapred against the useless shotgun, heal your medics, make yourself invulnerable. After some time I discovered that you are never going to use the shotgun because the 1sec rev up time of the minigun is very much worth the DPS.
Natascha is very good on Turbine because once they get out of cover they are dead. Most people think Natascha is for those who can't aim. Well, wrong. It's for preventing enemies from using cover at the expense of less damage.
The KGB is fine.
Seriously, people need to actually play the Heavy more and better before saying it sucks, because it doesn't.
The Heavy requires a lot of practise most players don't have. Most players die because of spies because they never turn around instead of being paranoid and turn around every 3 seconds while walking.
Most players don't jump-spin when entering a new zone, they move sloooowly until they see what's there.
Most players don't have enough tactical thinking so as to ambush the enemies.
Most players think that the Heavy should be able to stand against 6 different players shooting and you without any kind of problem.
At this rate all we are going to get is such an overpowered minigun that fires missiles instead of bullets. And everyone will still complain, because they rush, they don't plan and they don't watch their backs.