I never change to a fresh atomizer. It has never bothered me. You may have a little bit of the last flavor in there for a good 10+ drags. So if you do mind having a little left over flavor mixed with your new flavor, you would want to change. I personally like it when I can taste a little of the last flavor. I have come up with some real good flavor combos that way. My favorite so far: I was
vaping coffee, which I did not really like. Then I slapped some vanilla in a new cart and stuck it on the same atomizer. It tasted amazing. Now I always mix my coffee, half and half with vanilla and make what I call a vanilla coffee bean flavor. It is really good, and now I don't have to
throw all of the coffee I bought away.