I have tried cartomizers, clearomizers, e2 cartomizers, and the tank system and I prefer the e2 cartomizers myself. I tried the tank system and it doesnt produce enough flavor for me and clearomizers (ce2) all cracked over time which caused me to loose a lot of liquid. Now i just stick with the e2 cartomizers (same thing as clearomizers but with a better body instead of thin plastic). They dont crack and leak and one will last me almost half a day ( if i even leave it on that long; I change flavors a lot through out the day). I use those while I am out and about and then I use a lr510 atty while I am at home.