I would agree that theming plays a big part in differentiating the resorts (and thus selecting one). However, I would disagree that they have the same amenities. For example, one of the PO resorts has a boat to DTD, none of the others do (though presumably the other PO is close enough to walk over and use the boat).
We chose CSR specifically becuase of the two amenities which are unique to CSR among the moderates: high speed internet access, and a fitness centre. DH needs high speed access to check on clients (a working vacation for him), and BIL is an athlete/coach who will likely benefit from the fitness facilities. The fact that it's "less Disney-fied" and less "over the top" suits our family's tastes, too.
HTH
-Barbara