Alan - Mark's a top bloke & he's the ONLY tuner that i know of that actually takes time out to talk to you & answer any questions you may have.
I was calling him about twice a day for about a week before i booked mine in with him & i thought he might have been getting abit pissed off but he assured me that i could call him anytime if i had any sort of question's whatsoever!
Top bloke imo & probably the only tuner i would ever use again