well, i've been an NTL / CWC customer for about 5 years or so, and although CWC used to be a pain to get through to (and also in the early days of ntl), sometimes waiting 45 mins plus. For the last 3 years or so, I've never waited more than a few minutes to get through, and the last two times i've called them, i've got through within seconds of going through the push button bit.
Any problems I've had with STB's, after calling up, i've been offered an engineer visit the next day, and when he's turned up (on time), have spotted the problem and sorted it there and then.
I did have to have a STB replaced twice, as the one they put in was showing just a blank screen on some channels, but to be fair, you can't really expect the engineer to go through every channel and make sure its working - when he was here, the freebie channels were on, but my channel packs hadn't been switched on yet.
As for BB, I was the first install in Sunderland for the trial, and when they came to install it, well, lets just say they turned up en mass - 3 ntl vans, 2 ntl cars, and a manager in his car - god knows what the neighbours thought !! I've only had a couple of problems with the BB, one was down to a faulty STB, and the other was problems with the proxies.
On the whole, they get the

from me
And no, i don't work for them !