Goodness gracious, what a quality control disaster.
I remember when the first Vamo came out (circa 2012) and had a host of problems. Brass, easily strippable 510/eGo connector. A connector pin that would get stuck down. A chipset that was set to default AVG mode instead of RMS.
KSD didn't solve all of these problems until the V3 was released but by then, the damage was done. Take note, Smok.
I still have and occasionally use a Vamo V3 and V5 and for the money, they're still the best low wattage mods I've ever used. But I see them for sale at $10 or $15 on ebay and other clearance-type sites.
tl;dnr version: Wait a year or two for Smok to work out the kinks, and the GX350 will be a $20 .... kicker.