Just posting my results after having NTL CATV fitted 3 days ago in place of SKY
Installation: Excellent!! Ntl installers did everything i asked and more. Spot on job

Even gave me a seperate longer cable should i want to move the TV.
Box Supplied: Samsung

I asked them what box they would be fitting and they told me "i don't want a Pace box". Was made up with this after reading posts here!
Quality: On a par with SKY. Pleased with it. NTL lacks some of the functionality of SKY, but overall it isn't too dissimilar. Responses from the dreaded "Red Button" are also on a par with SKY
Overall, i am happy with the descision we have made. We are getting a mirror service from NTL for half the price of SKY. I think we'll give this 12 months (as per the contract), and see where both companies are at that point. If NTL do actually release HD PVR next year in response to SKY, i may well be sticking with the NTL product!
On a final note - Sky.
When i told them i was cancelling my contract they couldn't do enough, offering me this that and the other..... This was a few days after telling me that i would have to pay them £60 per month for a SKY+ service. Reminded me of those robbers at BT shortly before i ditched 'em....
Many thanks to all who have helped, invaluable info as ever