Eugene, only one I care about is the "suite upgrades at time of sailing." As for excursions, there aren't that many E and D cabins to make a difference. Even then, we have not had problems getting excursions even if we didn't book 180 days in advance.
edited to remove bad assumption ;)
edited to add:
For GRAND PRIX, my dates for excursions and dining reservations are still 180 (May 13) and 75 (Aug 26) days, respectively. I will monitor to see if this changes
