I've seen the Tesla Three, but never tried one... mostly because I prefer replaceable batteries and "adjustment" on my mods. I like the fact it has a big capacity (5000mAh), and the circuitry has a 40A cut-off, but the fact it throws a constant Voltage (much like a mech-mod, but doesn't drop off after every hit) does keep me from owning one... Many of my juices like a Wattage that puts my Voltage requirements in the 4.2-5V range, which I believe is lower than the output of the Tesla Three, which would mean my juice wouldn't get enough "juice" to produce the vaping experience I prefer.
I'm glad you're liking it... They're well made and from a reputable company, so don't take my desire to not own one as a negative... vaping is personal, and that mod just isn't for me