DS #2 took public transit from MCO to Orbit One Vacation Villas on US 192 to meet us there (we drove, he flew day after we left & we arrived within 3hrs of each other). Took him just over 90 mins & cost $2.00. He used
http://www.golynx.com/ to plan his trip. Although I dont have Summer Bay's exact address I see that you could take the bus to within 2.2 miles of Clermont using the Lynx trip planner. That would make for a very short & inexpensive taxi ride if you dont mind the bus. DS said most of the bus passengers seemed to be hotel/resort staff going back & forth to work & the driver and other transit staff he talked to were very helpful.
~Diane
ETA - just put Summer Bay's addy into the trip planner & see that it would take you 2hrs,21 mins (in the middle of the day on a weekday), you need to transfer busses twice & take 2 short walks (1 2 min, 1 3 min.) and cost $4.!! The directions say you need to walk from the MCO terminal to the bus but unless thats new DS caught the bus right outside the arrivals doors.