I do find the women in London dress up more. Well, than me, anyway. I am trying to up my game a little bit. I kind of relish the weekends for the jeans/hoodie uniform that I can throw on, but I do feel out of place if I'm going anywhere other than starbucks/sainsbury's/tesco, etc.
But I haven't really found anyone unfriendly, yet. I mean, sure, but nothing dramatically different than it was in my office back in NY. Actually, when I think about it, I found the NY women in my office a little more two faced, in terms of being polite and then catty behind your back. Here, I find the women are a little more straight forward.
That could just be my company, though. My firm at home was definitely more of a boys club so I think there was more competition among the women for jobs/projects, and that could explain the motivations.