I am SO glad this thread is here! I thought I was losing my mind..really I did.
I just got my M401 and have been using it for 4 days now and LOVING it! At first I was using the prefilled carts i had ordered to get me started, and while I was getting used to the whole process.
Then I got curious and wanted to try the eliuids I got from Pure Smoker. Suprisingly, I always hated Menthol analogs but LOVE the menthol juice! So I read up, watched the videos, and decided to try to refill some of my empty carts (scary stuff btw for a first timer).
I pull out the eliquid, VG, empty bottles, polyfill, my trusty paper clip, and go to work like a mad little scientist. A little shakily I mix and cut the eliquid careful to stay with the right measurements. I pull out the poly and try to decipher how much or how little to use based on the poly that was in it originally. I fill up my cart, adding the batting, and stick it back into the mouthpiece.
Then I find that my carts I filled myself aren't lasting at all! The prefilled ones were lasting me forever. The ones I was refilling were burning out before I could thoroughly enjoy them! I went from using 2 of my prefilled carts a day to 4 of the ones I had refilled! I thought maybe I was just such a dunce of a noob I was doing it wrong. Now maybe it's not just my inexperience after all. Which actually isn't helpful since it's still annoying to basically refill and/or top of the cart every time I pick the things up!