in the grand scheme of things, gold is probably fine, but here is why I like the platinum -- More bonus points --50%, rollover nights, and most importantly the ability to get a room when the hotel is sold out.
Now I may be a little jaded, because I am almost at 1000 nights, and will qualify for Lifetime platinum next year, and while upgrades in the rooms are nice ( been in the presidential suites in Monterey CA and Edmonton AB), but for the most part marriott has been good to me.
My only wish was that they would comp the parking for plats, but I can always wish...