After experiencing awful problems with my previous provider such as losing connection several times a day for no logical reason, I switched to O2 about six months ago. The previous provider frequently told me that nothing was wrong at their end and I should have the BT line checked at a cost of £150 but after switching to O2 at a fraction of the cost previously, I have not had even one problem since and enjoy six times the download speed I had before. I chose O2 because of the very high score they achieved in Which? magazine and this has been fully justified. The only problem I have with O2 is on my mobile phone as when I'm at home I can only get a half decent signal on the upper floor and virtually none on the ground floor although it's ok almost everywhere else.