Well I was a M+ user and have been for last couple of years, done around 2500 miles in all sorts of conditions and only 1 puncture which was a huuuge piece of glass...however, am in the process of changing them as I just cant get them on (at home, let alone when out in the bush). they are properly indestructible, so much so that the last few months I have gone out without any puncture repair kits/spare tubes etc as, well, whats the point. I could possibly get them off, put there is no way on Gods earth that I could get them back on...so, although the chances of getting a puncture are close to zero, I have decided that witth the increased distance I am doing, and the increasingly remote places I am cycling in/to, that I need to be able to change the tyre, so ordered some Michelin Pro4 tyres, will put them on this week and see if there is any difference rolling resistance wise although to be honest I just will feel better if there is a tyre on my bike that I can change should the inevitable happen!