I have a smoke 51. Bought it at a local smoke shop along with their disposable so that I wouldn't change my mind about trying e-cigs while I was researching different models. It was ok, definitely not great, but enough to let me know that I wanted to try vaping. I was still smoking the entire time I was using it. I ended up getting a Modern Vapor Sidesho because I wanted it to look like an analog. Ended up quiting in 6 days with that even though I actually was trying to cut down. I just ended up getting it down far enough I decided I should just go ahead and quit the ananlogs. I have a few different PV's, I'm just one of those people that wants to try new things. I love my Sidesho though. They produce lots of vapor, battery lasts longer than what you're using and customer service is great. I also own some 902's and Lux's from there as well. The 902 and Lux are both impressive. (using the Lux right now as a matter of fact).
Check out the suggestions and then do your own research. There's lots of models that give you good vapor. You may want to check out some of the video reviews too. It will put the size and performance in perspective for you. You can always pick up a disposable to get you through for a couple of days until you decide.