I have the Chrome Sigelei ZMax and the Black Aluminum Sigelei ZMax, and love them both!!! I use them with the Smoke Tech locking DCT and the vapor taste is wicked good. The black is much lighter, but knowing the longevity of aluminum threads, I am extremely careful when screwing on my tank. The threads do feel good, but aluminum is a softer metal and I prefer to error on the side of safety. Being that I tend to chain vape a good bit, both of my Sigelei models are my full time vape, and I have had no issues! I have found that one of my DCT tanks does not fit well and will cause a hard draw on the Black one, but my 3 other tanks, 2 Smoke Tech, and one Evolution tank work perfectly!!! I use dual 18350 IMR batteries in both, with my 18650 batteries as spares. Again both models work GREAT and have helped me to drop analogs altogether, IMHO you cannot go wrong with this device, I am even thinking about buying one in the Satin finish, just to complete the set... LOL
This pic is with the 18350s in the chrome and the 18650 in the black.
**I only use IMR batteries, and recommend them for these APVs!!! **