I would assume it would be the same service as DX has previously shown. Maybe try finding some feedback posts of DX laser purchases from the past. I know styropyro has posted a few reviews on them which include shipping times and service.
Lasers aren't illegal in the UK. There won't be any problems with customs.
I've no experience of Yourlasers, but O-like and Lazerer are both worth looking at.
I've looked at O-like and Laserer their lasers appear more expensive than the same "advertised" power of the YL lasers??
However following a bit of searching, as someone else has mentioned on this forum, the YL website doesn't have a secure checkout !!!!.
So I guess it's a case of you get why you pay for..so I'll take another good look at Laserer and O-like...I realy don't like the idea of sending my card details to a non secure payment page on YL.