I think no one (in their right mind anyway) expects Mark to produce a live show with the same energy he had 15-20 years ago. Or even five years ago. Ageing can happen quite rapidly when it first sets in. I think on the whole that Mark has handled the late phase of his career well and is "ageing gracefully", but in some ways I wish he'd let go of the more demanding tunes in terms of guitar playing as they clearly suffer. I don't know if it's just because of a lack of interest in technical guitar playing on Mark's part (and thereby not too much practice), or if it's a physical condition. A combination maybe? But he has all the right, after so many years, to say he's done with Sultans and the like. I forget the name of that blues tune he played on Bill Wyman's birthday concert, but that kind of guitar playing he copes with well. It goes to show it is possible to compose and perform rocking, fun tunes without guitar pyrotechnics.