I saw the Mistic at my local Truck Stop and since my partner is a truck driver with a fuel bonus points card for that truck stop (2 pennies per gallon of diesel purchased) I bought one on TA points, making it free, as will be cartomizers for it. I have had it 3 days, good warm vapor, nice TH, reasonable battery life. Does take 4-5 hours to fully charge but lasts 6-8 hours. (they claim 2 days but that depends on use) The biggest negative is refilling, the cartos are sealed units so, it's syringe or condom method ONLY.
I normally use a 510 with cartos, vapor wise it is comparable. I'll see how long parts last. for the price (15.00 cash) if it lasts and performs well for 90 days I'll be satisfied it's worth the price, beyond that and it gets to be a better value for an entry level PV.