Can't help with recent trips, but when I booked a rental car for December, 2005, the rates dictated that I pick up my vehicle at S&D rather than MCO. I'll be taking DME from MCO to my resort, then picking up my vehicle the next day. And for some strange reason (fuel prices, most likely), premium & SUV vehicles are less expensive than compacts at S&D--at least when I booked! I much prefer a compact, but for savings of $100+, I can drive a premium (full size with bells & whistles). The SUV was $15 less for my trip, but I don't want to drive one!
The difference in rates (no codes or coupons) between MCO & S&D rates (compact less expensive at MCO, so I'm using that price) was about $125 less at S&D (returning it to MCO).
Go figure!