(New Experimental patch as of December 12th)
#1: Infected have small inaccurate hitboxes especially for the head, or hit registration is not working correctly on them.
In some occasions, you can shoot them in the head, and they won't even get hit (no blood splat) it will just go through them?
(I'm chambering my FNX w/ ammo from my inventory, and shooting from short-medium distance for a pistol)
#2: Zombies aren't alerting to gunshot sounds in the new EXP build, compared to the old one from the 11th?
I shoot next to them, and they won't be alerted or aggro, but if I get close, they do.
(Medium pop server, was some lag?)
#3: Infected are still spawning in stuck on geometry, or running into and getting stuck on geometry (walls, doors, terrain, etc.). The only way to free themselves is if they attack you, or you punch them away from it