I voted POR but I equally like CSR. I think either one would be a magical visit. POR gives you the boat to DTD, shared amenties with POFQ and a fairly central location. I agree that the trundle bed may be a plus for some. You also give the families a choice of the rustic AB or the formal Mansions, designed around the Old Man Island, and none too far from main hub. CSR is the newest moderate and more deluxe feel, but POR has been through some recent renovations.
Further considerations may be: ages of children - pool or playground needs - both are great but different, use of food court - would style of CSR appeal to you, will you use boat rentals - I like the lake setup at CSR better than river set up, will you have kids who will be free to walk around hotel alone - would you like the idea of conventioners.....