Bet365 - excellent
Betfair - very slow - have to call them to get a proper answer
Centrebet - excellent
Gamebookers - poor. Slow and does not answer the questions asked. A problem with some bookies - when they cannot answer your question, they answer another one you did not ask.
Ladbrokes - same as
WillHill only not quite as bad.
Paddy Power - excellent
Sportingbet - CRAP. Dont bother with these guys...
UK Betting - OK. Only mailed them once and got pretty quick reply.
William Hill - When you call their call centre you are 100% sure to get some guy on the phone for whom you should think English was a forein language. They often dont know anything about betting or sports and after saying the same thing for 30 mins, you have to ask them to get the manager to call you back. Which he does - the next week! I dont know why they bother with these call centres - they are of abolutely no use!