I have a friend who I signed up in the AS MP a couple years ago. He thought it was "ridiculous." He has since had unplanned travels on KL/NW and rerouted by UA on an AA flight and got credit and now has over 50K miles and is comped to MVP based upon his UA status. If you really fly AA that much, you can always change your program for mileage credit at the airport (I would think) after your upgrade and everything is taken care of... and then you won't have orphan miles.