I"ve done the Mears shuttle twice now...once with the DU pkg, once without. It worked out great. Last August we were picked up, at BW, around 7:25, got to US/IoA by about 8am.
You do have to book it the day before you want to go, and be ready to either pay with a cc over the phone or have cash in hand when you get to the bus.
We were told to call Mears a few hours before we were ready to leave and they would give up a pickup time. That also worked very well both times.
It's a nice way to go. You usually head to US/IoA in the large full sized bus, but they use vans to get you back.