I have used Mr. Tuffy's. My experience was that over time they folded somehow inside the tire and formed a point, sort like the point you make when folding a piece of paper. Then, that point would wear away at the tube and eventually cause a slow leak. That happened twice. Now, I do realize that I don't have xray vision, so my analysis is is based on what they told me at the bike shop and what I saw of the tire liner after it was removed. But the "bottom line" as they say is that I had more flats with the liners than without. This spring, when I activate the summer bike, I am going to get the Scwalbe tires and see how they work. It certainly is possible that my liners were not installed correctly; I don't really know much about using them.