I'm using the smokelessimage volt right now. I cannot get these cartomizers to burn -- when they get low they start putting out less vapor and if I keep on vaping them until absolutely no vapor, it just gives that toasty taste like when dripping on an atty and need to add drops. I refill it, it's back to totally perfect. Nice warm vape, lots of vapor and flavor. I get 5 hours out of a filled cart and they only hold 1ml of juice. So now I'm not only getting a great vape, I'm using far less juice than I was before. Lovin' these things.