Seems no one cared to mention these strange bugs that came with Steam QL.

Sticky hitboxes:
When brushing by another player's hitbox there is an odd sticky feeling. Kinda like lag. Its annoying. I'd love an explaination. Obviously this bug never existed in pre-steam or any other quake title.
Edit: Apparently this bug has existed since 2012.

Hitting your head on invisible ceiling:
When hugging a wall after a rocket jump or a jump pad, you'll frequently hit your head on an invisible ceiling just before reaching the top floor/platform. This bug is very frustrating and shouldn't exist.

Grenades sticking to top of hitbox:
This is the least problematic nuance but again, it's a bug that shouldn't exist. You can now shoot a grenade at the head of an unmoving opponent and instead of exploding, as it should, it just sticks and spins until timed explosion. Kinda odd, and I really don't see why this isn't addressed.
3dit: also has existed since dawn ql.