The TV uses 1-2Mbit of the 'up to 8mbit service', but ONLY when the TV is in use. So if you get 7mbit you will get 5.5Mb in practice. If its anthing less, get the 4mb internet service (and the TV won't usually affect this much).
Relibility is good, I've not had an outage in six months and a total period of downtime of 3 hours in 2 years (I work at home). The network is also non-contended, so pings are extreemly low, possibly the lowest of any network.
I'd echo that - reliability is pretty good (as good as Telewest), speed, using an adslguide.org speedtest is as advertised minus the TV allocation, customer service is very responsive, the only downside is that the TV picture is poor (especially on smaller/niche channels)
It was pirrty much the only service I could go with 10 months ago. It was the best offer with no download limits (on the "max speed" 8mb plackage).
In comparision to blueyonder, (that I couldn't get here) the upload speed is far greater. Although I belive blueyonder has recently upgraded, or uncapped some systems more. I personally have found blueyonder to be far far far more reliable. There internet is rock. - where i once used to have it.
Thoughout the first few months had a few crashs, tv often had some blocking images and freezes for a while. Also the internet seemed to crash every few week. For the past 6 months its been fine. Peer to peer sometimes takes it down. But the box now seems to manage to reset its self. With 30 seconds your back online.