I've got a Masterbuilt 40" that looks identical to the MES 40. My biggest complaint is not enough smoke .
Maybe it's my choice of wood. The hickory chunks I normally use in the WSM won't fit in the chamber so I use handfulls of apple or cherry wood, refilling the small chamber three times during a smoking. Maybe there is a better choice of wood to use. My family won't let me near an ax to dice up the hickory wood since the last time I used an ax was not pretty.
I've noticed Bearcarver did some slip in modifications to his MES40 unit by adding an AMNPS pellet tray and some homegrown covers at the bottom. Anyone else have ideas on how to add more smoke, short of buying this AMNPS gadget?