I keep meaning to get around to writing this review. Like every time I jump on my CX bike to go ride the glass-strewn seawall and bridge route along the coast here, and I think "wow, it's been eight months since I've had a flat, I should write a review." To put this into perspective, I was having a flat about once every two weeks before I put these tire liners in. So, yeah, these things work like a charm. I'm using the less-expensive "Duro" version. At $35, they're not cheap, but I've more than made up for that in not buying patches and tubes, not to mention time and aggravation. They add a little weight, but with the short-tread offroad tires I'm running it's hard to tell any difference. In a nutshell, the bike rolls the same as before. It just rolls a lot longer between flats.
To recap: Eight months with no flats, up from a flat every two weeks. Light and thin enough that for non-race tires it's hard-to-impossible to tell that they're in there. Not cheap, but they've paid for themselves already. For post-TEOTWAWKI or just everyday use, these are good stuff!