I have a V3. As far as raw vape quality goes, I think it's one of the best. That's extremely subjective of course, but it gets closer to my particular ideal than anything else I've use, and I've used a lot. Airy, dense, and warm but not hot. Wicking is pretty straightforward and forgiving, and it wicks well while staying leak free. No special filling techniques required. I should note, though, that I run mine with either the tall or short bubble tanks. The standard tanks don't leave much room between the chamber cap and the "glass"(ultem) for higher VG juices to move around so you have to fill it slowly, which can lead to flooding.
Performance is great, build quality is great. Well, minus one stress-inducing area. The screw heads break off pretty easily. I'll admit that I'm a little heavy-handed when it comes to tightening post screws, but these are kind of ridiculous. To make matters worse, they don't sell replacements. I've searched, sent emails, posted in facebook groups, can't find them anywhere. I've used the spares so at this point I'm just not going to rebuild it until I absolutely have to. Very frustrating to say the least. I've wondered whether this is by design, but I think that's just the conspiracy theorist in me. Either way, I'll be damned if I'm going to shell out another $100 for a new one just because their shitty post screws have all broken.
Speaking of which, can anyone confirm that the screws included with the fasttech clones will fit the original? I've thought about ordering a couple just for the screws, but I'd like to be sure.
PS: subtanksupply has them in stainless and "gunmetal"(it's black). Ships from Kentucky.