One of my favorite tips was to use a town car service instead of Mears. We had a super great driver, the grocery stop was awesome and we didn't have to make 5 other stops before getting to our hotel! I will never use Mears again!
I want to echo this advice. I always book town car service going to WDW and here's why...
The first time we traveled to Disney with a child, we brought our 18 month old daughter. Our flight was 50 minutes late. Exiting the plane, our daughter had a "blowout" (all parents know what I'm talking about here) and we had to stop and deal with that, which made us quite tardy coming down the escalator to meet our driver. We had left our house at 4:30am and it was now on toward 11am, so you can imagine that our nerves were frayed.
Our driver greeted us kindly, sincerely asked if we were okay, and asked if we needed to take a moment to get a bite or anything. Understand, this driver is standing in front of us losing his next fare due to our lateness, and is asking if we need to take a little extra time.
We then discovered that our bags were left back in Philadelphia. Our driver took us to the appropriate little room for our airline and walked us through the paperwork. He then gave us a bunch of advice and asked if we'd need to stop to get anything before going to our hotel. We didn't, but if we did, the option would have been critical.
When we got into the car, our vacation began immediately. Hopping on a bus or getting into a crowded van would have just added more discomfort to our challenging day. When we arrived at our hotel, we were in vacation mode, instead of frazzled mode. It was well worth the expense and the additional gratuity I added on.