Ryan,
I think one of the hardest things to deal with with the Bradley, is having the faith you need that everything inside the smoker is fine. Having had some very mixed results with my Brinkman in the past, my first couple of Bradley smokes often found me hovering near the door trying to decide if I really needed to open it up to look, even though you know full well that it is not necessary!
IMHO, rather than paying for the window, use the money to buy a good dual probe thermometer (which you would still need anyway, even with the window). I like my maverick ET-73 just fine, as long as I replace the batteries regularly.
After a few smokes, you will have the confidence that you rarely need to open the door except to refill the water pan or rotate the racks every now and again depending on the length of the cooking time. Now, about the only thing I worry about is when the stuff goes in, and when it comes out. The Bradley truly does handle just about everything else itself, and that's one of the best reasons to have one.