well guess what, i have both... first off like eman said, i dont believe in leaving any smoker unattended. working around the yard, garden, house, or garage is one thing but sleeping... i dont know, sounds like a recipie for disaster.
you need to make some decisions, what is it you exactly want. if its perfect control with as little interaction as possible then the MES is for you. as long as it is working right. it has electronics in the controls and cant be left out in the rain etc... but if used in its limetations is a good lil smoker
the GOSM is almost there but not quite but it has advantages over the MES. portability is the first thing that comes to mind, great for gatherings etc... dont need electricity to run either. dependability, my GOSM has sat outside for over 5 years. it looks like it too, paint all faded and all but the important thing is the igniter has never missed a beat even though it sets in a snowbank all winter. have to shovel snow from the bottom so the burner gets air tho... was my workhorse smoker for many years.
guess i may as well plug the woodburner i got early this year too. just an el cheapo Charbroil SFB smoker. found this lil gem in a saver store for 50 bux in the box yet. and let me tell you, just doing it with lump and wood, no elec or gas, well it gets addictting. and after a bit you can get these to hold a steady temp just as well as the others... but thats where the next item really comes into play.
no matter which you choose, if you dont already have. get yourself a dual probe thermo with remote reciever like a Maverick ET-73, as far as i know it is the only one that lets you monitor both high AND low smoker box temps. great lil thermo if you take care of it.
i have all three and am not putting one over the other, yes i have my favorite but i wont tell you which one. why you ask??? its because those reasons are mine and your time is not my time. but i will tell you this. there are times i need to depend on one of these other smokers cause of things going on etc... well i guess that kinda let the cat outta the bag didnt i. but choose what will fit you the best. remember you need to keep it fun or it will not be a long lasting hobby like it is for so many of us here. whichever you choose let us know and show us your creations!!!