If people are being genuine in asking questions, giving input, or whatever then bitcointalk is at best a neutral place in terms of friendliness, and that's if those posts are being read at all. But as soon as a person shows themselves to be a sig spammer or someone out to use this forum as a place of employment, forget about it. You'll see the daggers come out faster than you can blink. Personally I have no problem with that, because there are so many idiots here that they need a firm hand applied to keep them in check.
As long as I've been a member here, the vibe has been prickly at best, i.e., there have been a lot of members at each others' throats. That's quieted down to a large extent since some of the prickliest members have left (Lauda, TMAN, Vod, and numerous others), but overall the vibe still lingers.
I think sig campaigns also kind of keep people in line, for the most part. Those who don't have a real feel for the lay of the land here either
a. walk on eggshells out of fear of losing their campaign spot, or
b. dive head-first into sections and topics that they have no business in,
with the majority of posters falling in camp a.
Its always funny to me to see a newly-purchased account taking part in Reputation topics, as if they can kind of slip in and nobody will notice its a bought account. Doesn't happen so much anymore as they tend to get slapped down pretty fast these days.