I hate BT. I was with them for only a short time, but it was long enough for me to realise that they are pretty useless, and when things go wrong it's impossible to get through to them to talk to anyone (unless things have changed).
I'm with Sky now. I'm paying less with Sky, for broadband, phone and TV, than I was paying BT for just phone and broadband. Rarely does anything go wrong, but if it does their customer service is first class.
You don't sit on the phone pressing buttons and listening to horrible music because you are answered by a person who puts you through to the relevant department, if they're busy, they will call you back.
Every person I've ever spoken to at Sky has been incredibly helpful - maybe I've just been lucky, but I think it's just the way it is.
A few months ago my Broadband disappeared - nothing to do with Sky, someone tried to fix the problems with my laptop after I installed windows 10 (that's a whole thread by itself) and lost everything.
Got onto their technical department and a very patient, helpful man got it sorted out for me. It took some time as everything had to be more or less reinstalled so we were on the phone for some time but we got there in the end. All it took was one telephone call.