As I know https://cex.io is UK based exchange. At least that's what it said to me on the bank statement when I made a withdrawal from there.
There were announcements that he would have his card, I don't know what the status of that is.

I saw they have "Lowered fees are for GBP deposits made by UK residents."
The only thing that I think is a disadvantage here is a slightly lower trading volume for the BTC/GBP pair, maybe not for bigger players.