I have a variety of Kanger toppers in my rotation, among others.
Still have (and use) a couple PT1, a PT2, and several T3S and MT3S, and a couple of Evods. Some Unitanks and PT minis as well.
I find the Evods too small for my regular vape, and a little tighter on the draw. And the MT3S is always a challenge to see the juice level, got to have a good light!
Most have been "upgraded" with the air flow control bases (except the T3s and Unitanks!), and I rebuild my coils.
I find the Unitank to be an under-appreciated device. With the right coil and wick build, they're fine little units. Simple to use, and easy to fill with no mess.