The first question I have, as a PP asked -- what's the budget???
Yes, you are correct that the over the top, in your face, theming is the values, and the least are the deluxes.
However, the price of the deluxes is, generally, adjacent to a park - which means you can either monorail, launch, or even walk right into that park. Moderates and Values are bus transportion=not that there is anything wrong with that. The GF, Poly, WL and CR are all adjacent to MK, while YC/BC/BW are walking into Epcot resorts. With the age of your son, I would highly recommend staying near MK as I'm certain that will be the park of his choice.
One of the favorite resorts we stayed at when the kids were young was FW in a cabin. There was a lot of upside as it has launch service right to the MK, you can also take a different launch to the CR and then take the monorail to the TTC and take the Epcot monorail from there right into Epcot -- which is 8 minutes and a young child would enjoy a lot more than the bus ride. Nothing like flying in over future world!
A couple of other benefits of FW for a 4 1/2 year old -- there are lots of activities that would interest him. Pony rides, petting zoo, chip and dale's fireside marshmellow roast, hay rides and more. The cabins have a bedroom with a full bed and bunk beds and there is a murphy bed in the living room -- so, I'm pretty sure his bedtime is earlier than yours, which means you could put him to bed and then be able to relax without disturbing his sleep. The cabins also have a full kitchen as well as a deck with gas grill. There is only 1 bath, but we have made it work with up to 5 people in the cabin. Also, given that he may be tired, it is nice to be able to take the launch back and let him take a little rest in the afternoon - the launch probably takes 15 minutes running time.
The price of a cabin at FW is about 15% higher than a moderate. Just an FYI, both WL and AKL are deluxes, but are at least 20% below the price of the other deluxes -- and can be bargain shopped at times - -They are both BEAUTIFUL. The drawback to AKL is it is adjacent to AK which means it is far away from everywhere else. Because WL is not on the monorail, it is a launch only to the MK, but as I said, only 15 minutes.
I hope this helps.
Tom