In reply to ianghogg:
We did the TMB this September, and I think you'd get on well with something more at the walking shoe end. The only problems feetwise we had was from some blisters where girlfriend and forgotten to wear in her shoes, and pain from path impacts. Although the two main higher passes were a bit scree-covered, I don't think you'd necessarily been any better off with scrambling boots, whilst the large amount of hard tracks/roads lead to some quite sore feet (particularly the long down hills - although we did go clockwise, which may well be worse for this), so extra sole cushioning would have been much appreciated (I used some custom made summer weight unlined leather boots with a foamy sole, and my girlfriend used some mammut via ferrata shoes.
We did have only 1 afternoon of rain though, so may have been a bit different mud-wise if weather had been worse (only one muddy climb to the southern high pass for us).