Is it? I've had 2 Smok ZMaxs'. Each one's fire button stopped working after ~2-3 weeks. First time I sent it back to Madvapes for warranty. Second time I said "F it".
I ordered a Segelei telescoping ZMax yesterday in hopes that Segelei has put together a better, more reliable unit. And you're not the first, nor second, maybe not even the third person I've heard that from. Plus I REALLY want to like it; I think the telescoping ZMax is awesome. In part because I have 18350, 18500 and 18650 batteries. Lots!

But I also really like telescoping mods.
I'll post my review after a week or two of owning i.