I bought mine from a stealership outside London (Bucks), cos I thought it'd be cheaper but still they charged me �250 for the second service.
I only did this there because as someone's mentioned before I have a number of issues with the bike under warranty(rear disc buckled, front brake light coming on way too late, bike engine stopping on clutch engagement and lastly, stiffness in the steering).
Bike was over a grand cheaper to buy though from them.
BTW Nick, depending on where you are in London, I know of a good/reliable guy near me in Sunbury