Graham: That Fitness First is probably the best deal I think you'll get. You might be able save a few quid, but if the machines there are up to date, i'd take it.
The gym I go to also has a free refridgerated drinking water dispenser which is nice. They also sell bottled water and Lucozade if you are so inclined. It is by the best I found researching and FF doesn't sound too far off that.