First off, I'd like to add my support to the unofficial forums Zhaine has set up.
The queues on LOL were horrendous but recently you're looking at 30 min MAX queues and usually 10-15 mins. Yesterday I was in a queue of 500+ and suddenly about 200 I was in. Really not bad at all and I think it's a small price to pay for a heavy pop server.
As for nationality, very occasionally you'll see some non-English in general, invariably followed by "sorry, bad chat ", so any rumours you hear about the server being "invaded" by Czech, Portuguese or any other nationality are simply not true.
I've grouped with people from countries other than UK and unless you start asking where people are from, you'd never know.
The FPS on the fleet can be pretty bad but not unplayable.