I have had my joye 510 for 6 days now and I love it. It gives me the vapor and the feel of smoking a cigarette. my friend has he m401 and I like it a lot but wanted to get more vapor with each pull. I have enjoyed my joye 510 so much i have showed it to all my smoking friends and they all couldn't believe that it felt just like smoking a cigarette minus the chemicals, I think I have changed the views of most of my smoking friends. I think I have gotten a few switching already. The joye 510 truly is the best out there in my opinion.