I guess the actual speed is a function of many variables. I have just uploaded a 15MB archive via FTP to Norway with an average of 55kB/s - that's not bad, but close to what I had with HC, too.
Downlink speed is much better, and it should - after all I'm paying much more compared to HC, so it better be good!
I like, however, that the routing seems more efficient, at least to those places where I "travel" most - you see, I'm a long-haul telecommuter to the US west coast (aka Silicone Valley). I've had insanely poor routing (as in: many hobs and long round-trip delays) from BT, reasonable routing from HC, and am now enjoying the best-ever routing with NTL.
So, I guess the bottom line is that performance judgement is a very personal thing. HC was pretty good on the stability of the service, we'll see what NTL does in this regard, long term.
Some argue NTL throttles by using transparent proxies on HTTP, and I must confirm that HTTP downloads are not very exciting with NTL. Even though HC also uses transparent HTTP proxies, their performance, relative to the subscribed bandwidth, appeared better. Might just be fewer users, though. However, HC's proxies screw you up on RPC over HTTP, so bye bye Exchange Server IMAP access via Outlook...
There are so many individual requirements and variables in all this that I seriously doubt that ISPs can be ranked in a way meaningful to many. Stability and reliability of service might be one "common denominator" aspect, but otherwise... You've gotta jump into the cold water and hope you're not getting a chill.
Make sure all your stuff is ISP-independent, e.g. set-up your own, independent email system, etc. Once done, you are at least able to move on once the minimum contract period is over.
Hth