Since I am Platinum I feel I am been given better rooms in Marriott FS and Renaissance in Europe (did not try other continents, and I suppose in the USA Plat is much common). I don't know if I will ever reach this level again, but if I stay loyal to Marriott it's good for me to have been Platinum at least a year as it is a prerequisite to the Marriott lifetime Platinum status.

Other point : if Marriott policy does not change, after Platinum you will have a "soft landing" to Gold. Interesting if you are not sure to make 50 nights in 2011.