I import from absolutelyecigs.com and I have had no issues. I find the vapor production out of my m401 blows my DSE 901 out of the water. I have noticed differences in vapor consistency between e-juices, though. I find my oriental provides more than my virginia or my french pipe. I find that coffee makes awesome vapor, but it has a smell my wife can actually detect. Powerpuff makes great vapor, too. Oh, another thing about the 401. Sometimes I find the filling in the cart can get pushed down. Use a paperclip and bring it level with the top of the cup inside the cart, and that helps with vapor. Also, do you drip/dip? Even if you don't, I would recommend a bit of liquid on the wick of the atomizer to get things flowing.