been using hello-016 for two weeks now. i love this thing. great vapor production, super long battery life. i did an experiment on the batt life the first two days after full 8 hour charge as per user manual. i let it go two days before it died on me. i am a fairly heavy vaper. as an example when i use my 801 i have to switch batts at least 6 times a day, that should say something about the batt life of the hello. coneamizers are not too terribly bad either. if you like the 510 i would strongly recommend the hello