I have had Ntl BB,TV & phones for several years and apart from a few e-mail & proxy faults last year it has been fine, what part of the country do you live in? The fact that the original cable equipment came from many different companies can mean that some areas are better served than others. If you're lucky enough to be in the North West then you also get the bonus of some of the best CS staff that I have encountered, anywhere.
As Scooby said, new customers usually get some kind of offer.