The (first) reason i think its common to many models and not just echo i think ego for sure. For echo the echomizers ( cartomizers) for ego the atomizers. These things might perform well or they might not, for example burning taste ( i tried to push the filler down still no change, left it overnight to settle etc) or not having a full taste, the taste you should have. To give you a number out of 10 echomizers from 2 different ventors 6 were bad straight away and the other 4 were good but (second)lasted no more than a week with pg juice. I think the same thing applies to atomizers for ego. A (third) reason was that it was to airy. I vaped yesterday an ego-t from a friend (same juice) and it was much better. I went prepared full battery full cartomizer. But my main concern is for the echomizers, if that was ok then i wouldnt mind so much and i would continue to like echo as it is a good looking device and i like automatic batteries. I think that there are people who will say for both echo and ego that their atos cartos last almost a month but there are also people like me.