The Dolphin's location is wonderful. Great views and right next to everything. If you're a Starwood / Marriott rewards member you get all the perks and points of that program. It has upscale dining and amenities, a great pool, spa, fitness center, a beachfront recreation area, and 24-hour food available. The beds are Sheraton beds and comfier than Disney moderate beds. Some people are company-loyal, so they don't like that it's not run by Cast Members, but you get most perks except the airport shuttle. I've stayed at Dolphin/Swan often and would do it again.
By the way, I love POR's relaxed atmosphere, resort design, food court, and the wonderful boats to Disney Springs. I'm not as much of a fan of the motel-style moderate resort layout, where the window is at the corridor so you keep getting people walking in front of your window. I feel like the great views from the Dolphin/Swan make them really special (even if they're not Disney-operated).
If you do arrive at MCO early in the morning or late at night, you can still get on the Mears shuttle but you might have to pay the driver cash since, since as of last visit, the driver didn't have a mobile credit card machine. The shuttle desk will have an after hours phone number posted, but when I called it, they just said to proceed to the pickup area to meet the driver.