I recently had the same upgrade urge. I ended up going with the Atlantis because it gave me the option to
buy BVCs if I was feeling lazy, but they are not hard to rebuild. The one caveat is as the ohms got smaller,so did the time a
tank would last me. I ended up carrying around
juice bottles anyway. I ultimately ended up with a Hobo clone a couple weeks later and it is about as easy as you get for building.