Recently, I shopped for a backup for my Provari. SS was a must. I looked at the Evic and passed because of the rotating ring for adjustment (felt a little fragile). The Tesla was interesting, but has a slot down the side that exposes the battery. That's a cool looking feature, but it lends itself to dust in the contact area. Tesla is also a rather large tube with molded ridges down the side and only comes in aluminum from what I was told. I guess it resembles something Tesla would have built and does that quite well.
I was looking for something stainless with a slim profile like my Provari. The Siglei SS Zmax Telescope was priced right at $74.95 in my local B&M store. I'm not crazy about the telescoping tube, but that allows you to screw the bottom up and down to adjust the length to fit most any battery rather than installing extension rings (something you have to keep up with).. There's a standard spring loaded battery cap on the bottom like the Provari and the cap has 5 holes on the bottom for venting in case of a spewing battery (which hasn't ever happened to me on any mod).
The ZMAX LCD display is sharp and very readable, even in bright sunlight, although you might have to turn your back to the sun to shade the display for better readability. Once you use the menus a few times, operation becomes second nature. ZMAX gives you wattage and voltage options (3.5-15 watts in .5W increments or 3-6 volts in .1V increments). It also displays the resistance of the coil you have installed and will display the voltage or wattage in RMS (root mean square) or Mean (average) mode. You can select voltage, power, or atomizer resistance to be displayed every time you hit the fire button.
Listening to the sound of the coil through the drip tip, it's obvious that the electronics are operating at a lower frequency than my Provari. I'd compare it to a snake rattle hiss as opposed to more of a smoother hissing sound in the Provari. That's preferential, though. The vape from my ZMAX is much the same as the vape from my Provari. With an 18650 battery installed, the ZMAX is 3/8" longer than the Provari. That's not an issue. It still fits fine in my pants pocket and can use various button top batteries.
ETA: The atomizer sound changes if you go from Mean back to RMS. In RMS mode, it sounds smooth like the Provari. Interesting.
An installed Kanger Protank leaves just a tiny clearance between the ZMAX tube and the bottom of the Protank. That may be a good thing because it allows more airflow to the atomizer. The Provari with a Protank is a tight fit with no light between the two and seems to bottom out on the trim ring at the tube top just before the threads hit bottom. Either works fine with the Protank.
Maybe others can give you a review on their favorite.
