Thanks for the suggestion will look into the Ritz card. At a quick glance, looks like there is a bonus free nights offer for Ritz and not for AMEX (except the 1 night on anniversary)....but I think i'd be more likely to spend the $300 credit of AMEX at Marriott/Starwood than the $300 airline credit via the Ritz card.
Any other differences? I guess either one would be the only way I could get Platinum via 75K spend