Yes, do be aware here, Marriott, Hilton and IHG get a bad rap on upgrades, as most of their inventory has only a few suites. As opposed to Hyatt and Starwood who build more suites into their properties and therefore have more suites to upgrade to.

At Marriott FS I find I'm upgraded virtually without exception, usually being "concierge floor", "exec rooms", "larger guest rooms" and "corner rooms". Now admittedly my 500 nights have been mostly EMEA but of the 3 stays (10 nights) in North American Marriotts I have been upgraded every time, at the Marriott YYZ to a corner room, the Marriott Philadelphia a concierge floor room and the Marriott Ottawa an exec room. And of course I received lounge access at all 3.

In reality the only uptick in benefits as a plat are the arrival gift ($10F&B or 500points), the 25% extra platinum bonus points and the 48 hour availability. It's not a great step up from Gold, hence when I failed to make the numbers a few years ago I didn't mind the bust, but I certainly have been determined to make the stays to keep gold, no matter what. I don't want to lose those room upgrades, breakfast and exec lounge access.