I'm trying them for the first time although I have used another brand. It seems the whole "technology" of bottom coil/syringe filled has the same set of problems and weak points. I looked at my desk the other day and have a total of five differnt styles of delivery systems, none of which is perfect to say the least and several are so terrible I'm amazed anyone has the nerve to market them. I am hoping this new, reworked, vastly improved, solution to every ill in the world delivers on at least some of my expectations, but I won't be all that surprised if it doesn't. Guess I getting even more cynical in my old age. There is always the olde reliable, the carto, when I get tired of leaks, burnt taste, syringe filling, tweaking battery posts, making sure I'm standing in the right relationship to the earths magnetic fields, checking the solar flare level and all the other little "tricks". All I want is easy, dependable and repeatable.