I started with a Greensmoke (808-D2) cigalike and have used tanks and cart-tanks. I filled my own Greensmoke-compatible cartos and ended up buying four 808-D1 batteries (808-D1 seems a more widely used standard) and still find the 808-D1 setup with a cartomizer to be the easiest, most consistent vape of all of them.
The only downside in my opinion is the cost. I rarely refill cartomizers for practical reasons, but given the time and money one can spend on exotic attachments and materials and putzing, it seems like that's really a wash.
The only downside in my opinion is the cost. I rarely refill cartomizers for practical reasons, but given the time and money one can spend on exotic attachments and materials and putzing, it seems like that's really a wash.