What I found refreshing about David and Mary in TAR 10 was their wide-eyed innocence about the world - and not just the traveling. They will not be innocents abroad this time and that may diminish their appeal. It will be interesting to see how they manage with other experienced racers. Will Mary's open heart win her friends or will she find every one else to be as rude as she found Dustin and Kandice to be.
I was surprised by their re-done physical appearances when they filmed the "Finish Line" segment, and felt it diminished my initial image of them. But if this experience helps them to grow and to know, then I say all right - good for them.
I know I'll be listening for Maryisms and have fingers crossed that she hasn't become worldly and sophisticated.