I started with an automatic M402 with PCC i liked it very much, then i moved to the M402 manual batteries, i was using my M402 (two batteries and one atty) for almost 6 months, then i saw the M201 and got one, great TH (better than the eGo and eGo-T) and battery life, the only thing i do not like about the M201 is the leaky cartridge.
I have introduced a lot of friends to the vaping, and almost all of them are using M401/2 with PCC.
Like one month ago i bought an Absolute Maxx (i think is an eGo clone) and a eGo-T, they perform well, but i still using my M201.
I really do not know whay the M series are not that popular, but i think they are great for first time vapers that are looking for a similar to an analog e-cigarette.
(sorry for my english)