TF2 got the polycount update and the Mann Store.. there is simply to many things to comment now, so I will focus on just one for now.
The new Sniper Set complete bonus gives you headshot immunity... this really change the way snipers wars are played. However, given how rare hats are getting one to complete the set is hard.
You can get most of the weapons either by random drops or trading, but I doubt anyone would be willing to trade his croc hat, making the set bonus a pay-only privilege, and these are 17USD right now, or 20 bucks for the complete set.
Can't say I am totally happy with and I am actually surprised to see game changing upgrade with a price tag.