The eRoll is a very good device, other than very limited battery life and such a tiny tank -- but they've just come out with a new model, and a new PCC (portable charging case) to go with it, which will charge and store 3 eRolls, and also store 3 extra tanks -- a much-needed innovation!
I actually quit smoking using an eRoll, the older ones that only charged/stored one, with no storage for extra tanks. It was the constant charging-shuffle and the very tiny tanks that finally made me go looking for something with more capacity; my first non-cigalike was the iTaste vv3 with a Kanger T3S on top, and that made such a huge difference, I put the eRolls in a drawer and left them there. Until I had that month of smoking and trying to get back into vaping; one of the problems I faced was that after 4 days of not vaping, vapor no longer tasted good to me, so the eRoll was great to get back into vaping, since it mutes flavors considerably compared to a real tank.
But what I discovered was the eRoll's real flaw, to me, was the lack of variability; the vv3 (and the several other variable mods I've bought since then) have spoiled me completely for non-variable devices; I even got a Kick when I got a mechanical mod, so I'd still have some variability, and the ability to set a given wattage and have the vape stay the same, rather than declining as the battery charge declines.
Andria