I like the Protank, and have had good success using 32g kanthal and hemp, which gives me a really robust yet airy TH.
The only negatives are:
1) They are a bit fiddly. You don't have much room to work, and you must make sure to get your wick/coil low enough in the cylinder so that the insertion of the post doesn't put metal on metal and short it out. I can wrap 3 1mm hemp strands, barely, but am going to try two and see if I still get a nice hit, and a bit more leeway in terms of keeping it stable.
It's very easy to thread the components just slightly "off", and then you get leaking problems. But if you thread it exactly right, it shouldn't leak, and you can tighten the threads without worry of losing draw, due to the architecture and the air holes at the bottom of the base.
2) I want a Protank on which I can place a drip tip! I've gotten sort of used to the metal, but over time the SS coat is bound to degrade, (I guess exposing brass?) and I much prefer acrylic on lips to metal.