We used ME when we travelled to the World in January 2006. We only booked it on the Wednesday, for Sunday travel, so we didn't have the yellow ME tags for our bags. We did clear U.S. customs at Toronto airport, and flew Westjet, for what its worth, I don't know if airline makes a difference.
The greeter at Orlando directed us to the ME counter, where we were shown a folder with pictures of different types of suitcases and bags. I pointed out the closest ones to ours, and told them the colour. They took a copy of my baggage claim tags and sent us to the bus.
We arrived at CSR checked in and went out to dinner at the Boardwalk. When we returned to our room around 9pm the bags were there. Everything intact.
I thought it was a marvelous service. I hate waiting by those carousels for the bags. Mine always seem to come out last. It really worked out well for me, because I was travelling with two kids, and no hubby to help with the luggage.