I would recommend getting the EVO from intellicig.com. They seem to go into extra care to improve quality and get a more stable product. The EVO is and m401 design and the parts are interchangeable but the EVO is really far far better than the generic m401. I ordered 4 atomizers from intellicig with
batteries. I tested each atomizer with 36mg liquid after draining out the factory PG. They all performed roughly similar with great throat hit and consistency. After my pleasant experience with the EVO I ordered 10 kits so that in case things get banned or in short supply I will have adequate hardware. (just being paranoid.)
I am convinced that the EVO is the very best e-cig available.
PS I have tried 4 different e-cigs including the Janty kissbox. I have not tried the screwdriver yet.