More players is always better, you can ignore them when they're unruly and take advantage when they aren't.

I really haven't noticed a problem on DC US, though I also don't consistently pay attention to it. When I have though, it's seemed ok. If people were cursing left and right, that would definitely get old fast. Mostly it's the stuff I'd expect -- guild recruitment, LFG, random questions. Occasionally, if someone gets too spammy bout it, people start whining about it, but in general I actually really like seeing an active zone chat. I like knowing there's other folks out there playing the same MMO, letting me know when a dolmen in up and chattering away. If I want to play solo, I'll fire up Skyrim.