I absolutely love my EVO. Although I did have one faulty battery that wouldn't activate a week after receiving it, that John promptly replaced. It has EXCELLENT vapor production for a device of its size. My first Atomizer lasted only about a month before it started to have a problem producing vapor. Didn't bother them about it since it may have been a result of a drop that bent it a little and shortened its lifespan or my direct dripping after first week almost exclusively. My replacement set of atomizers seem to be better constructed too. It has more vapor then the 901, but, not quite the same throat hit. For me, since I smoked lights, I prefer the EVO over the 901. My only dissatisfaction with it, is about the same as the 901, that only the end of the cart nearest the atomizer really gets dried out so even though the vapor production starts rapidly diminishing, there is still a lot liquid in the cart. Anyone recommend a model that really hits the whole cart?