I had an njoy that i toyed with for a couple years. I only used it at work, then back to my analogs. When I got back into vaping my rn4081 died. I purchased a dual 510 kit from good prophets and never looked back. I consider my 510 my first because it was the first device that I used to seriously quit smoking. I chain vaped so fast I could hardly keep them charged, but they showed me that here was something better out there. Ive gone through most of the basic mods, and some more technical mods, but I still have my 510 batteries and they still work. I broke them out the other day and took them out for the night, the reminded me of when I used to inhale till i was about to pass out trying to get a head rush. I might even get a pcc for vaping in public. Im still partial to good prophets just because this little 510 kit has lasted this long, so not to get too mushy, I still love me some good prophets products