It's definitely a "pick your poison" scenario.
I used to have BT Broadband and it worked great, yet when I moved house they couldn't offer me a speed above 1Mbps - which I felt was unacceptable seeing as I live in a town centre.
I have Virgin cable for broadband and a BT phoneline. The broadband is excellent, fast and reliable, but Virgin customer support isn't very good. In fact, they told me I didn't live in a cable area when I called to get the service installed, despite all the other people in this set of flats having it...