Unnecessary yes, but most graphical effects are unnecessary. I play multiplayer games with HDR simply because I think it looks nice. I haven't felt it's damaged my gameplay, and while it doesn't really do anything to improve it either, I'm glad it's there for the added eye candy. It might give you a slight disadvantage but I've yet to feel I've been killed due to having it on, and I don't really take online gaming seriously enough to feel the need to maximise my advantages. I can definately see why people would want it for for serious matches and the like, but that's not me, so I'll keep it on
Oh and if it crashed twice in one evening and very rarely in the past, I guess that sounds like the update caused it. I've had hundreds of crashes from source engine games, mostly due to switching between hammer and source but not exclusively, hence my comment about it hardly being the first time







