We have stayed a few times at GDT and many many times at CSR, definitely our favorite moderate on property. Our thoughts on the GDT differ than most as far as rooms are concerned. 1st we like the standard view rooms at GDT better than the water view...when we stay in the tower we always ask for a high floor, standard view, and eastern side so that we can see fireworks from Epcot and DHS, but now that may not be a thing anyway. Once while staying in the tower they had the x-wing ships flying around that were built for the opening of Galaxies Edge...was very cool. While we like the GDT, we actually prefer the rooms not located in the tower...not because the rooms are not great, they are, but because for us it is way easier to get around the resort from a central location. Pools, food, quiet pools, walks are much better for us. The tower is nice, but we love the beautiful open spaces right outside of your room at CSR, and the tower just feels tight to me.
You can't go wrong with either location as the property is beautiful and as others have said...great food options, great bar options, great pool options...options!!