I can't comment on the Wailea Marriott specifically, but I have stayed at about 3 different Marriott Hotels in Hawaii on points before. Everytime I stayed (Kauai Resort & Beach Club, Maui Beach Club back when it was a hotel, JW Ihilani on Oahu) they all three upgraded me to nicer view or even suite rooms. What I might do would be to try and find out how crowded the hotel is (i.e. do they show availability for lots of different room and view types?) If they do, I'd probably chance it and ask for a Plat upgrade when I arrived. I'd rather save the 140K for something else.