Haven't noticed much difference in flavor between the LR 1.5 Carto for the tank tube and the 3.0. But the 1.5 gives a warmer vapor. But still, I actually prefer the 3.0. Why? I really can't tell you, I'm too new at this, still trying to learn all I can about cartos, tanks, atomizers, drip tips, a.s.o. Don't like dripping, though, I learned that! . Killed one carto for the tube because it clogged, I stuck a needle down the air tube, and I guess I mess it up. Couldn't get any air through the tbe anymore, no matter what i tried. Lesson learned, don't stick a sharp needle down that little tube..... LOL!