I've just gone to Bulldog, I got fed up with NTL customer services.
I signed up for 4meg and got upgraded to max 8meg before connection.( Interactive Service)
I was on line 16 days from sign up, first day 7.8 meg since then usually 5.2 to 5.5 meg, it did get down to 4.3 once.
I didnt see Buldoghell until after I signed, most problems seem to be if you are changing from one ADSL supplier to Bulldog.
If you are new to ADSL and dont mind a new phone number its O.K.
I tried to get some information from Bulldog Customer services before signing but never got to speak to anyone.
The contract is only monthly so I will be cancelling if there are problems.
The minimum guaranteed level is 2 meg.