I've been using the Nockturnals for several years and i agree the mechanism for turning off the light does get messed up periodically. That said, I still like these the best overall. The NuFletch Igniters look like they would work well if you don't mind adding the nock insert to your arrows. I like that you can just use the Nockturnals right out of the package without any added weight or work. Price wise, they seem to be comparable to the NuFletch Igniters.
I agree, and that is why I have shot them for years. It is just frustrating when a you get a pack and they may be done after one shot. I actually still have one that I have been shooting for 3 years now and it functions great. I am sure there is fault in all of them though, I was just curious to which ones other people liked and used.