I could never recommend NTL.
Requested Broadband and TV combo last year. TV was set up fine, broadband didn't work (engineer said they had to do something back in the office). After about 2 weeks of phone calls, broadband eventually works (albeit much slower than advertised, but that's common enough) - for a week! Cue phone calls and emails. Every time you ring them, it's the same thing - "this is the first we've heard of it", "unfortunately we can't do anything right now", "an engineer will call you".
For 6 months, between myself and my landlord, we logged over 40 phone calls, 8 emails and a snail mail. Over that time, an engineer came out twice, admitted their was a problem with our local box (for the neighbourhood) and would fix it. In both cases the fix only lasted 2-3 days.
Refused to pay the bill after that and they eventually cut off our TV as well!
From what I know, with NTL - if it works, it works well, but if you have any issues, well, burning in hell sounds like a better experience than dealing with their customer service!