EDIT: OP, I understand your frustration. Although given to me as a gift (so I don't feel so angry when it happens), my first generation Lavatube won't fire every single time. I have to press the button twice every once in a while. Irritating, but not discouraging.
Several of my friends who bought the Zmax as soon as it hit the streets are now saying they regret their purchase. One got the Smoktech, the other got the Siegele (I know I just mangled that word).
On the Smoktech one, my friend was ...... that his plastic digital display window came loose of its own accord. He's like me, he handles his PVs like a delicate lady. Actively thinks ahead not to drop it, won't put it in a place or position that it can drop, etc. It just... poof, popped off. He was able to push it back in, but it wiggles and comes back out occasionally.
On the Siegele (sp?) one, my other friend was pushing dual coils at 12 watts (not sure what that averages out to in voltages, I'm horrible at math) and he got a LOW LOAD screen and it stopped firing altogether. I'm pretty sure it was user error on this particular thing, though.
I'm holding out for Vamo stories. I'm really eager to get my hands on one of those. But I want it to be out a couple of months and see if any horror stories start rolling in about it. I am definitely getting a Provari mini at tax return time.
Once I get those two, I think I'll be a very, very, VERY happy vaper. My journey will be something something something dark side something something something complete. ;-)