Ive never really noticed the DM's to have bad efficieny, there comparable to most other guns.
they get around 8 and 1/2 pods stock
but for smoothness and quietness, long dwell and low lpr will make that happen.
grab a bag of paint and some air and experiment, you cant really mess them up to where they dont work, and you will probobly find the settings you like, and if not you can just reset it to stock, which works great.
"If your too busy getting even, you will never get ahead"
-a wise man