SPG program is upgrade friendly (read suites) for Plats. Marriott's programs is not upgrade friendly even for Plats, although it requires the most nights 75 to qualify.

another example
 

the MR program needs some TLC from the execs. another fine example of inconsistencies throughout the program.

Just checked into the Marriott Amsterdam for 9 days (yes, enough to identify me to any staff checking, I know).

I was told no upgrade from basic room was available (full stop - no part/small upgrades). I thought fine so I went up and dropped off my stuff in my room. I went to meet a colleague in the Exec Lounge, but it turned out that my key hadn't been enabled, so off downstairs again I went.

I thought that I'd take the opportunity to prod the staff on why I didn't get an upgrade - and after a talking to a couple people I was told that the reason I have a standard room is that no other rooms were available for the 9 day stay because one or two nights were really busy.

Fair enough I thought.. I just thought that I'd check online seeing as I was in the lounge looking at something else. Sure enough - one (corner) Executive room available for the 9 days of my stay. Pretty disappointing. I'm not going to spend my time arguing with front of desk staff, but the Manager is getting a complaint. If I'm not going to be offered an upgrade then don't promise me one - it's a pointless thing in this hotel anyways, but don't expect demanding frequent travellers to roll over when promises are taken away and people are being lied to.