I never tried a Smokin-it, so I can't tell about it. My Son had one that worked fine, except the top vent, which was right in the middle of the top used to drip down on his food.
He needed to add chips and/or chunks often like any electric smoker, and the smoke was never consistent, just like any other electric smoker.
My MES 40 is over 4 years old, and I've never had any problem with it. The Amazing Smokers complete the circuit making an Awesome smoking machine. I can keep perfect temp & just the right amount of smoke for up to 11 continuous hours (Bacon, Pork Butts, Brisket, etc) without touching anything.
There are some Gen #1 MES smokers that have had problems, just like anything else, however the Gen #2 has a much, much greater chance of having problems.
Bear