Personally, I think it is worth it for two people. It is not the least expensive way to go, but you receive more than just transportation to your resort. We have used it for me, my DH, and DD; I have also used it for trips with just me and my DD. TTC's help with bags, the grocery store stop, and the direct delivery to your resort and then the airport are all very valuable services. I have only used TTC and have been very happy with them. I know there are others and board folks seem to like them, too.
A few years ago we had TTC scheduled during the time of a terrible blizzard here in Michigan. We were really late coming in; I called TTC to tell them we'd be late, but didn't know when we'd get there. Well, when we arrived in Orlando, Ronnie was waiting for us at baggage claim. Naturally, our bags were not on our flight. Ronnie knew everyone at the airport and expedited us getting our bags. Then he took us to Goodings, where again he knew everyone. Anyway, we were hooked and really appreciated their good work.