I have come close to purchasing these a few times, but have always had 2nd thoughts and put them back on the hook at the store. Now I am sure I will never get any of them. From what I have seen tinder-quick has no way to fail they have always worked for me. But then I have used dryer lint or lint scraped off my pants more times then I can remember.
I once decided I needed a hi-tech lighter I got a Brunton that cost over $50.00 it quit in a couple days and I went back to a Zipo I have several they all work. I carry a small fuel bottle and spare flint in my gear.

Jim