QUESTION OF THE DAY??
If staying on site and flying in, Are you using Magic Express?
Are you as afraid as I am that you will not get your luggage until 10pm at night and will miss out on swimming your arrival afternoon, and then will have weepy kids who don't have their 'jammies to sleep in??
Why have I only read horror stories about ME?
We are staying offsite and have a mid-size SUV rented, so we will pick up our luggage and go

.
When we stayed onsite in 2009, we used ME and Disney transport exclusively. While it was okay (no lost luggage, etc.), I doubt we would ever use it again. We like having our stuff with us, and didn't like being at Disney's mercy as to when our luggage would eventually be delivered. And one standing-room-only trip home from AK after the masses were soaked ... and smelly

.....after a rainstorm was enough to help us find the value in being able to hop in our own vehicle to get back to our resort.
That said, I can definitely see why people choose to use ME to its fullest (like we did on trip #1). When you are paying premium prices to stay onsite, you want to take advantage of all the included perks offered as part of your package. Saving the cost of a rental (ours is $251, taxes included, for 8 days) helps offset the higher room rates at Disney resorts.
Should we ever do an onsite trip in the future (which I doubt, but ya never know) I am 100% sure we'd still get our own vehicle (as we love

the freedom of being able to explore all the other things Orlando has to offer) which would negate the need to use ME.