I don't care about other classes, but leave spy bodyblocking in permanently, it's fucking awesome.
Things spies can now do which are awesome:
-On maps with ledges, edgeguard. A well positioned spy has a new way of killing unaware players.
-Two spies can perform a real pincer attack. One spy comes from an enemies right, the other from his left. They sandwich him, one shoots at him to keep him distracted, and the other stabs for the kill. This is an excellent teamwork incentive and makes the stereotypical crowd of failspies actually more effective in their numbers.
-Dropstabs got nerfed in a good way, since they're now objectively harder.
-Facestabs got buffed in a good way, since now it's really disorientating to hit a spy and you can trick overzealous players into being stuck in your stab. One may also pin players against objects like crates with perfect precision timing
-Spies now have an extra function: detect other hidden spies. When two invisible spies collide (something a spy can't otherwise prepare for), a pistol duel ensues immediately deciding which one survives. This is invariably awesome, seems like a reasonable replacement game ability for the now nerfed quote bubble, and makes for some nice spy vs. spy.
-Standing still and being a campspy got nerfed- if another spy touches you while you're standing still, they'll know you're camping but you won't know they touched you, making you an easy target.
-You have to be more careful how you travel, and you can't just derp into a crowd, m2, m1. You must plan your actions.
Basically, it massively buffs the spy's potential skill ceiling, and it really adds a lot to the game. Make this shit permanent.