Well, there certainly are a number of prominent British users, like NEVR and NintendoMadness (friends of mine, you could say, in Clubs & Crews and Wi/Ht), and there are of course others. Still, the BBS that you know is only a small part of the total voting, submitting, reviewing population of NG, and not really a representative one at that... So while I might say that the Brits have a good presence on the BBS, I wouldn't say that there are any more of them than there are of United States or Canadian users.
Well, maybe Canadian, but not USA users.