Out of curiosity, you said you weren't doing an R4 until you found an alternate fix for the vent and possibly waited to see if valve fixed stun stick bug i think? Speaking of that, I cant really recall if that stun stick bug is ONLY on R3 or if it's any time you are combine or have a stun stick. I've already made my suggestion with those grenades on top of the bathroom center divider thing. You cant shoot xbows over the top of them even though you are shooting like 40-60 units above them. Thats annoying as hell. If you cant fix it, no worry. I just wanted it for my l337 xbow shot from bathroom. Other than that I'd have to say my only other pet peeve in R3 were the different window textures. I like how they break, but I dont like the altered visibility...also not really so important.
OH AND ONE MORE THING! PUT THAT BOOT BACK IN THE RPG ROOM!