I've been using a Segelei ZMAX V3 Telescope for a few weeks now, I love it. My son went with the Tesla from iVape. They both have nice OLED readouts that give readable information. The Segelei has a larger well and has no problem using a Kanger T3 clearomizer, while the Tesla's well is just a bit too narrow for the T3 to fit but it will take a CE5. Other than that they are both very nice as a main PV. Also, they can both survive being dropped, repeatedly. I had considered going with the Kamry K200, but wattage can only go as low as 5 and is adjustable in one watt increments. It also has a non linear voltage output. Setting it to anything between 3.0 and 3.7v will result in an output of 3.7v. Above 3.7 it seems to work correctly.