I just got mine this week. I am a vivi nova user, but I was intrieged by the way the rebuidable coil is mounted on top. So far it's working great. Tons of vapor and good tast. For someone who wants to rebuild their own coils, it looks promising. I need to use it longer to form a better opinion. So far, the quality of the tank doesn't compare to the vivi nova and refilling could be made easier. It's made to refill with a syringe, but I've been unscrewing the bottom to fill it. i think with a few changes they could have a winner.