I have a old style MasterBuilt 30" with a new controller. I only use it as an inclosure for cold smoking because of poor temp. control. A lot of folks on here love there MasterBulits. I think it's a good box for cold smoking.
I have the 40" model with the window two years old. It is actually number 20070211 but there are so many numbers that I don't know them apart by that method. I suspect the "...0910" unit is a 30" model, don't have a clue about the other one.
I love mine. It has a remote that is useful to show you what is going on without having to go out to the smoker and a window to clean. They make a 30" that is about the same and both 30 and 40" models that have no window. I thought the 30" would be perfect, but they had the 40" on sale for about the same price so I bought it and have been thankful ever since. I can smoke two burgers, or a mixed package of 40# of meat in it and it works fine. There is a bit of a hot spot on the top shelf over the heater, but I just check it a couple times and move stuff around a bit if necessary.