We choose based on:
Consideration #1: who is in our party and their ages and mobility issues. When my son was little, we usually stayed on the monorail. With my arthritic parents, I chose to stay on the monorail. When it was just my sister and me, we stayed at a moderate with a lot more walking and waiting for buses. Now that my son is grown up, when it is DH, DS and I, we have more options.
Consideration #2: I think about my budget and try to get the best bang for my buck. For our upcoming trip, we were originally booked in a one bedroom at BLT. Disney came out with a 30% off discount, but, for BLT, it only applied to studios. (The discount was only 5% for BLT one bedrooms.) However, the 30% off did apply to BCV one bedrooms. Both BLT and BCV were on the family Disney bucket list, so why not save 30%? BCV, here we come.
Consideration #3: occasion. If it is a quick weekend trip, we will be more flexible about where we stay and what type of room we choose. If it is a celebration, we'll do deluxe CL.
Consideration #4: We prefer resorts where we already know we like the restaurants. This is part of the reason we love GF and AKL. Although we liked WL, none of the dining options tempt us, so we probably won't be back. BWI doesn't appeal to us because we're not that crazy about the idea of having to walk to the actual boardwalk to eat, nor do we like the boardwalk restaurants we've tried. (We are dining at Kouzzina this trip so that may change.)
Consideration #5: Crowd. I don't mean the demographic who book a certain resort. I'm not even sure that Disney resorts have specific demographics. I mean the number of people. In our view, the smaller, the better. So, Pop Century with its 2880 rooms has less appeal to us than, say, the Yacht Club with 621 rooms.
We don't think too hard about distance to theme parks because we usually rent a car.
Hope this helps...