I chose the cookshack model 009. It was more expensive but no mods were needed, no water pan, well constructed and insulated and to me it is true set and forget. I literally (depending on the size) will throw my brisket or butt on the night before with a couple of chunks of wood and wake up the next day and wait until the temp hits what I want, pull it, foil and cooler, then eat.
Size is the biggest issue with the cookshack. Ribs have to be hung or cut in half. Briskets 12lbs or less and even then you have to kind of hump them in the middle until they shrink. However, I have done 2 8lb butts with no problem and could probably fit 4.
I seriously looked at the MES and if money had been an option I would have gone that route. Since money wasn't as much of a factor I went for build quality and the ability not to have to add wood every couple of hours. In fact if I had it do over, I would probably have stepped up to there new digital model that is larger and has a automatic hold feature when you meat gets to a certain temp.