We did the opposite (Disney-Universal-Airport) and just rented a car. We did take DME from airport to Disney, then picked up a car at the Car Care Center and dropped it off at MCO. Honestly, I'm not sure whether it was efficient, price-wise or not, since it cost $20/day to park at Universal. But it was nice having a car. My son ended up leaving his MB (which is attached to SOMK, so actually has some worth to us) in the rental car shuttle and so I drove back to Disney to pick it up the next day. It was nice to have the freedom and flexibility to do that.