I would stay with Caribbean Beach, as I had for 12 previous vacations.
Coronado Springs does seem more geared to conventioneers, and I would not ever stay there b/c I love the conveniences of a foodcourt, yet do not want to pay an extra charge for gratuities. That's a rip off, annoying, and unnecessary.
PO French Quarter is too small for me, all being on one side of a lake. I know that you can explore "upriver," but it jsut isnt for me.
PO Riverside and Caribbean Beach are very similar in layout, design, and amenities. Tose are my top two picks. Just pick the theme that you feel you would enjoy most, antebellum South or tropical Islands. When I go to sunny Florida, I want the tropics and thus enjoy the ambiance, beaty, and relaxation of Caribbean Beach, and its better location of feeling more connected--you can see/hear segments of Illuminations and view SpaceShip Earth. And remember that Riverside is going down for rehab soon (so it might be needed) and that PO FQ just finished rehab, and Caribbean Beach did a tad over a year ago.
I would shy away form Coronado for its pay extra foodcourt. BLAH!