I think the welcome new member get depends on how they treat existing members. But that's true anywhere; If you purposely piss people off you're bound to encounter problems, especially when you're new because nobody knows where you're coming from or whether you're joking or not.
The UK community is pretty good, with occassional exceptions but that's normally after work posting which isn't always a good idea.
the only thing that frustrates me about the UK site is the lack of NSX meetings in my area, but that's hardly surprising when most of the owners live in the southeast.
If I was going to bitch it would be about new members slagging off targas and autos or trying to find a black car or a type R, or existing members obsessing about their NSX model collection or debating the pros and cons of sodding test pipes!;-) However none of these truly bother me.