I have little to add to the three comments immediately below. If you just want the fastest & most reliable ADSL broadband possible, THIS IS IT!

No gimmicks, no throttling & an excellent control panel. Peak period is 8am to 6pm, Monday to Friday. For £17.57 per month, I get 1GB peak & 50 GB off-peak usage (other plans available). I have been with AAISP (Andrews & Arnold) since July 2008 and have never exceeded the 1GB peak usage; I just make sure big downloads are made after 6pm or on weekends. BRILLIANT, I cannot see any reason not to give them 10/10 across the board.