Regarding your initial question: I would not know. It is certainly not the model that QVC has been selling of late with no window. You should be able to get a lot of info on the
Masterbuilt/MES smokers under their respective headings; might also be a better place to ask some specific questions.There is a fair amount of information on
Smokin-it on this site. You can also look over the units and forum at
Smokin-it. If you search for smoking-it smokers on
Amazon, you will see many comments.
What you decide to get will be strictly up to you.
Regarding the SI units, you may want to compare them to the SmokinTex line as well as the Cookshack line and get what you feel is the best value for your dollars. All (SI, ST, CS) are good. All are constructed of stainless steel inside and out with insulation. Heating elements vary by model and the CS is digital for a more stable temperature, but at a price. Some features are different as well, important to some folks, unimportant to others. Also be sure to look at capacity relative to the price of each unit, the warranty, and cost of accessories and or replacement parts. Look at the whole picture.
Many folks are fine with the SI or ST as is and don't worry about the temperature fluctuations and get good results; some want more accuracy and build or purchase a digital controller and connect it to their analog controlled smoker.. Some will spend deep for a Cookshack to get the digital capability built in. In the end, you need to hit each of the companies, see what they have to offer, and ask the company some very pointed questions regarding their use, reliability and accuracy based upon what you read here and elsewhere. And don't feel embarrassed in writing or calling the companies making these units. It is your money, not theirs.
Good luck.