Well, you could just skip over the eGo thing, and the carto thing, and the Protank thing altogether and get a mech and an rba. You might end up there anyway, I did, and I wish I'd not spent all that money on all that other stuff before getting there.... and nothing vapes like a well set up rba.
Just sayin....
What about the learning curve? I think small steps are nice because you get to learn what you like. For instance- if a mech mod runs at 3.7 volts with a full charge, I can set my spinner to 3.7 for a few days to test it out.