The view is the only difference (and as noted, Disney's "waterview" could mean anything from a full view of the river to an obstructed view of a birdbath LOL), and the rooms with the best waterviews, along the river, are further from the main building/food court/bus stop than the less expensive standard view rooms.
At resorts without balconies, I don't think paying for an upgraded view makes much sense, since you aren't all that likely to hang out on the walkway outside the room to enjoy it. And I think it makes even less sense at POFQ, because that upgraded view that you may or may not take the time to enjoy means being further from the amenities that you're likely to use every day.