Hi. I got my Sparkplug last week. Not a freebie - I actually bought mine. I also have PureSmoker's Prodigy and Protege in my PV arsenel. Cyberwolf is correct in that the SparkPlug isn't fancy. But after the switches going out on both my PS units, I'm starting to think that fancy isn't necessarily a good thing.
I'll be able to say more about the reliability of this unit after I give it the test of time, after 6 months or so of use. For now, all I can say is that it does seem to work very well. Hopefully it will continue to be a reliable unit due to its simplicity. I didn't have to go out and
buy a multimeter, tap on things or adjust things. It just works! So far...excellent
device!
The way the button sits flush on the bottom takes some getting used to. And if you're a woman with long fingernails, you might have to trim the nail on your finger of choice. No problem for me though. I like it.