L.P.
With so much to check, be sure to have a credit card handy, they want to be paid for checked luggage right there at curbside. It is convenient, but if it's cold or wet it's worth going indoors and standing in line. The disney plan is a good idea if you are staying at a disney resort, many people we talked to during our disney stay told us it worked flawlessly. We had reserved a private transfer, so we claimed our own luggage and like another person recommended, stopped at a walmart on our way to disney. We stocked up on breakfast foods, bottled water, some adult beverages before we checked into our room and that saved us $ during the stay.
Have fun!