My first ecig was purchased at a local flea market from satisfying smoke. It was an 808 model. I was told that since I was a pk a day smoker that the 5 pk cartos would last me a week. Well, I have not touched a cig since, but my vapin' was much more than smoking (since I could now smoke in the house). I was starting on my third carto a day (Satisfying Smoke didn't tell me that I could refill them) so I asked my sister-in-law what to do (she had been vapin' for almost 2 years). She told me to get the 510 starter kit from Cignot, which I did, and ordered some E Liquid to go with it. I really liked it but just was not as satisfying as the 808 battery to me. So, I ordered 808 batteries and cartos from various sites and I use both of the models now. I was going to try the Ego and was researching and ran across the E Power. Well, I purchased that in the 14650 and then had to have the 18650 model since they both used the 510 atty's that I had plenty of and the batteries are cheap and last a long time. Beginning to think it was a bad choice because I can't find replacement switches for them. I now have a couple of the Ego 650/PT batteries and I like them a lot. Still, if I had to choose, the 808 model has the better hit for me. Oh, and I use them all.........lol. Sorry, didn't mean to write a book!