If you want an e-cig that is good all around including, pretty good vapor production/throat hit, portable size and decent battery life, than this is a good e-cig for you. I have one of these and a 505s and they're pretty similar in most ways. I was a die hard 505 fan, but i think i actually like my 901s better now, which is saying a lot. If you like the 505, you'll like the 901, but if i could only have one model, I'd probably still stick with my 505s. Anyway, YOU CANT GO WRONG WITH THE DSE 901 FOR ALL AROUND PERFORMANCE.