If you calculate your cost of getting from MCO to WDW and back and then add whatever it'll cost to get from WDW to SeaWorld and back, I'll bet you're pretty close to the cost of a Dollar rental car. No, I don't work for them, I've just found them to be the best all around bargain at MCO. At WDW it's great to have wheels to visit resorts and AK. AK busses seem too infrequent to us. We lost 1.5 hrs getting from AK to MGM kast March. We'll drive next trip.
Bill From PA