You are already staying at what we call the "deluxe of the moderates" with amenities you will not get at the others. For $100 extra per night, I would stay at CSR then go to AKL and eat meals there, animal watch and appreciate the beauty of the lobby. Both offer cool lounges and good transportation. Whatever you choose will be amazing and a nice upgrade from ASMo.
In terms of rooms you will not find much difference at all in the rooms other than a balcony and unless you have a savanna room the balcony is useless. We've had pool view and would never bother again, we were out at all the public areas animal watching. The rooms have a few more feet that creates a foyer and more private wall between bathroom but not much else. And again unless you have a savanna room that is one resort you are not in your room but out exploring.
Dining - you can still dine at AKL no matter where you stay and the extra money would allow you to have more special dining on your trip.
Pools - yes you can only use pool at your hotel but while the AKL pool is pretty we have never stayed or visited when it wasn't very busy with loungers scarce. Two small hot tubs which are in very lush surroundings but usually busy. The pool is very geared for young kids in design with the zero entry at one end and the slide at the other ... there really is no adult area. With our kids now grown, that does not appeal to us if we have a lot of pool time planned. At CSR we have always been able to get loungers or tables. The AKL pool bar is much better all around in theme, size and atmosphere.
CSR: Beautiful resort day and night, walk around the lake at night = stunning. Yes convention but they stay in their area and the plus is the pools and buses are much less crowded. Top notch bus service. One of the best pool areas with counter service and bar right there with adult sized slide and biggest hot tub on property. Excellent "food court" better than AKL and all moderates. Found the resort quiet and relaxing and most times have pathways all to ourselves.
AKL: Stunning lobby, animals viewing, great eats (you don't have to stay to enjoy any of those). Indoor corridors which are nice is the weather goes bad. Balcony can be nice if you have savanna room. Something to consider is that there is no where to walk. You walk inside the hotel. No pathways, no lakeview ... the focus is on the animals being free and you are the one who is contained. May seem like no big deal to most, especially with young ones, but some adults enjoy that stroll or walk in the mornings or evenings ... it's not possible here. I would have to say if you think you can get $700 of enjoyment out of animal watching it might be the place to stay. We LOVE it there and would gladly go back but to lately I've not been able to embrace their rates as there is so many things I could do with that money......
.....Cirque (my DD & DS have been to many and say this is the best they've ever seen), dinner at California Grill with fireworks, Dining with Imagineering and so many other things that are above and beyond for my trip experience!