I was a BT customer for over 10 years and never had any problems with them! I know they are really slow to repair a line but other than that I can't fault them!
As for sky I have nothing bad to say about them, when I was with them I never had a problem. The turn around for repairs was three days. I found that with NTL it's next day which is good but that may be cause they have a depot just down the road from me!
When I used to call sky I would normally have my call answered within five mins, this could be as much as 20 mins if there was any majour problems but this was very rare!
Everytime I call NTL i am either on hold for anything up to 30 mins or I get a message telling me there is 50 or so people waiting for an advisor and to call back???
50 customers on hold for a company the size of NTL and they can't cope????
The only reason why I went for NTL was for faster BB as I could only get 1MB via my BT line, and I thought it would be easier to pay for all services in one!
How wrong I was!
I love NTL's services and when everything works all is ok, but once you call customer services for anything god help you!