The body is the strong feature of an MES and is very good.
The electronics and even worse, the wire connectors, are the weakest areas.
The wire spade connectors can corrode away super fast which is annoying becuase they will often cause your safety limit switch to heat up and melt down. These are by far the most common failure parts of the MES. Easy cheap fixes BUT fixes none the less and the effort to get to the safety switch is a pain if you don't have the tools to cut into it and you are like most of us who didn't have the rarer units that already have an access panel to the switch.
The top controller fails next most often but now there are replacements on
amazon for that.
I always say that getting a free or cheap used MES is the best one you can get, then clean (car wash sprayer), rewire, and slap a PID controller on it and you have something better than a $1,000 electric smoker and way better performing than anything
Masterbuilt makes brand new. This is like a completely different beast of an electric smoker and for a price often less than a new MES unit.
Also once these changes are put in place, you can keep it running through anything short of being hit by a tornado and repairs are easy, super cheap, and few and far between .
Armed with this little bit of knowledge you can ensure an MES unit always serves you instead of you being completely let down by it :D