Started with an AGA T and T+, best bang for your buck. Cleaning the tank does require you to take apart the whole wick/coil assembly.
I don't have a ZAP, just a Zen Mini, but the cap does tend to pop off easily. If you happen to have a long drip tip, it makes it that much easier to pop the cap. Just push the top of the drip tip ever so slightly, and POP! I do love the amount of vapor from this RBA. Would I buy a ZAP, definitely... I like the look on a Provari. Call me a collector.

I also like the fact, that I can remove the tank without taking the wick/coil assembly off.
After picking up a Cobra, it has a very stiff draw. Tip: If you don't want to bore out the air hole, just inhale very slowly. Would I buy another Cobra, definitely....one to put on display.

Just like the ZAP, I also like the fact, that I can remove the tank without taking the wick/coil assembly off. I may end up increasing the diameter of the air hole to match my Zen Mini.
Now, if you want something different, try a Terminator-C from Stormy's Vapor Cellar. Cool rebuildable that gets the job done. Variable flow control valve, puts you in control of how much juice gets to the wick/coil. Be sure to wash thoroughly to get that machine oil taste out.