I am now a Virgin Media customer as we moved to a cable area and the broadband is 100% better than BT.
I found BT Vision good in the sense that you have the recording function but in terms of variety of things to watch either playing on the various channels or on demand I thought it was terrible. They played the same thing over and over. The films were often either not updated or repeated and the box itself always crashed and/or updated at the one time of day I would be watching tv lol.
The broadband was a complete rip off, we were lucky if we got 4mb during any day (obviously worse at weekends) whereas Virgins saving grace is we have between 10mb and 20mb at all times. And it is far cheaper.
Once my contract with Virgin is over I shall be switching to Sky (I have never had sky but feel it will be better for me)