I was an early AMP Tank user. It seemed like a winning combination - the great taste of an atomizer in a tank. The flavor was much better than my tank cartomizers, but it leaked and was fidgety and unpredictable. I would take it with me wrapped it in a paper towel when it was in my backpack or pocket and the paper towel would invariably collect juice every time. Although I got pretty good at taming it, I was always concerned that it was going to leak. I found that the quartz tank was fragile - some people were having problems with it breaking when putting on the bottom cap. I broke a quartz tank when my mod fell over on a table (I've accidentally bounced a Pyrex OCD tank off asphalt without a scratch).
After I got a Killer and Divers I put my AMP Tank up on the Classifieds and got about what I paid for it. I now use Divers exclusively. Instead of having a special tank that uses standard 510 atomizers you can get a submersible RBA that goes in standard tanks. The taste is just as good as the AMP Tank, I can build a wick and coil to my desired specifications using my preferred materials, and it's as dependable as a cartomizer tank if built properly.
A Diver is less than half the price of an AMP Tank and so much better in my opinion. If you're comfortable with RBAs, I would suggest that you skip the AMP Tank and get a Diver instead. I have five and I use them in 22mm standard OCD tanks (IBTanked). I don't have much of an interest in buying other atomizers or tank systems as I've found something that works very well for me that I plan to use for the long haul.