The official Platinum benefit is "Priority Late Checkout" - but I've tested the late checkout policies recently in a number of international Marriott's and compared them to the results of non-status/non-MR members, and there seems to be no difference.

I was in the JW in Phuket with a friend (under separate reservations), and we both separately asked for late checkout. He's not in MR, and I'm a Platinum - we both got 2pm. I tried to extend mine further, but was told I could not without a fee.

I spent last night in the Renaissance Harbor View Hong Kong - this time with a colleague that has no status (again - separate reservations). We both requested late checkouts, both got 2pm. I asked for later (I could have used 3pm, as I had a meeting until 1:30) - but was again denied.

What's the point of posting this "perk" of being platinum if there's no difference between what you get and a standard member receives?

I'll continue testing my theory at the JW Bangkok later this week.