We took DME once, but usually rent a car one way (pick up at MCO and drop off at the Dolphin) or take a towncar service (car rental is usually about $40, towncar about $50). With DME, we were surprised at how long it took us to get from the airport to the resort (over 2 hours), so we took a cab upon return to the airport.
We only bring carry-on luggage.
So, give it a try and see. I'm glad we did, as I found out it's not for us. I like using a towncar, as they're waiting right there in the baggage area for us, and we get a quick grocery stop on the way for toiletries and drinks/snacks. It's worth the extra $$ for us, but YMMV.