The M401 suffers the same curse that the M201 suffers from, needing to keep the center hole open or divert the airflow some other way.

The m201 is a great atty, very close to the 801 penstyle without the leaking problems and built stronger with greater juice capacity. It is overlooked by most modders infavor of the 801 because of the air draw works much the same as the m401 and you cant just smear epoxy or putty all over it and expect it to work.

They both require a more careful and thought out build, but they both would make great modded e-cigs.

I build my personal mods around the M201 and M401 for personal use, maybe when I get better I'll have to start spreading the love.