Yeah, actually my brand new SL worked great at first - just after unboxing. It set a small strip of birch bark on fire without a problem. Then I tested it more and it began to lose "power". I couldn't light even the fluffed up brand new TinderQuick with it. (And yes, I was turning the wheel according to the arrow.)
So it was kind of tricky. If I had put it into my PSP or on keychain after first successfull tests, I might have been quite surprised later.
Which leads me to the advice that many here has been saying too - test your important gear often and always have a backup (same function, but different kind of the item).

I don't want to bad-mouth the company, it's just my experience. Actually I was disappointed that I would not be able to carry it because I liked the idea of a very small ferrocerium firestarter. But I had learned that this concept (tiny sparkers with wheel) is too much of a compromise. Now I carry the smallest orange Light My Fire firesteel and don't mind the extra weight at all.

Lighting a tinder with one hand using a simple ferrocerium rod and striker can be done. It's not super "user friendly" but it can be done. There is a thread here ( http://forums.equipped.org/ubbthreads.ph...true#Post158258 ) with some ideas on how to do it. I posted a video there but the links don't work now. If anyone wants I will reupload it.

Anyway the Sparky from UST looks a lot more reliable because you have accsess to the ferr. rod and therefore option to strike it with striker/knife if it fails. I might purchase it in the future to try it out.