TBH, I have had BT vision for more than 6 months and the service is very poor.
For the avoidance of doubt, my DSL connection runs at about 7.7M and I can get around 7.6M download speeds... although that was when I used Plusnet! Since switching to BT the throughput tends to be lower - but that is anecdotal only!
I have never once been able to watch a film without at least 3 failures, usually more. I have spent hours on the phone to BT - a call that I paid for at 0845 rates. They have had me reset the v-box (loosing all my recordings), reset the router, disable the fire wall, disable the wireless, disconnect my PC, etc, etc. Nothing has ever worked.
To be fair, it has got better, in the early days I could not watch more than about 5 minutes before the system failed. But last Sunday I put on a film for the kids and their friends and 5 times I had to restart because of error messages.
Take my advice, don't get BT vision. The basic BT broadband service is, at best, mediocre and the BT Vision service is poor. Just to add insuilt to injury, the video content available through BT vision is not very impressive either.
Why is all this so bad? Because you're locked in for 18 months!
=================
Life does not cease to be funny when someone dies, any more than it becomes happy when someone laughs.