In the absence of any other reply, Which? places it 6th out of six TV and broadband suppliers. "Mediocre customer score (50%)and pricey offering means there's little reason to opt for BT".
Incidentally, their top choice was Plusnet....good customer service and tech support, reliable and good value for money.
Hope this helps!
We switched from Sky to Bt a while back and have found the service much better and cheaper than the one we were getting from Sky. We were on normal Broadband which kept dropping out on Sky but with Bt we have Fibre broadband which is much faster. Only once have we had a problem with the service and they sorted it out very quickly. You can't record as many programs as Sky and some of the features are different but we find it fine for what we need. Also with the Bt box if you decide to leave at the end of the contract you keep the TV box and it will continue to record freeview TV and the pause and other functions will still work.
We have found customer service to be very good but not everyone will have as is the same with all of them. A while back Plusnet got very bad customer reviews but now it seems they are good. Also Plusnet are owned by Bt so to get the same service from each of them I would have thought the price would be similar.