I have been a Platinum Marriott Reward member since the early 1980's and have documented each of the reward devaluation changes. The current devaluation is excessive especially in light of the current economy where hotel chains are attempting to satisfy their frequent quests and not send them to their competitors.
Regarding the concierge lounge topic I have just returned from a trip to Chicago and stayed at one of the Renaissance properties. There has been absolutely no change in their presentation both in the morning and evening. When I questioned the Marriott employees about continuing their fine service I was told there would be no changes.