It certainly seems to depend on where you are in the country. In about 2004, my exchange was broadband enabled and I was recommended to use Plusnet as my broadband ISP. I have been with them ever since and enjoyed faultless service - oh and even a free domain name when their e-mail address database got hacked. That problem is now long behind them and the domain name I acquired is proving very successful in promoting my holiday cottage. On the rare occasions that I have needed technical assistance, it has been excellent. I rarely think about the system - it just works and, about half a mile from my exchange, I get up to 6Mb.
P.P.