My only experience of factory servicing was when I had Astons - to say they knew how to charge was an understatement! I was charged £12 labour for putting an umbrella in the boot - not kidding.
I will stick with Bell & Colvill who know my car and go the extra mile for me.
On that note, I was very sorry to hear that the founder of Bell & Colvill was killed a couple of days ago. Shot himself accidentally cleaning a loaded shotgun.
http://www.getsurrey.co.uk/news/surrey-news/witty-knowledgeable-always-enthusiastic-hugely-13905762