I travel for leisure with week long stays on average but at multiple Marriotts for 4-8 weeks at a time. Currently Gold, hitting Plat soon, travel mostly Asia but have done most continents. I've come to not expect any kind of upgrade unless I ask. I usually check in late evening and if it's important to me, I'll ask in advance.

I have a few different tricks.

My most recent one was after a problem arose while I was at a JW. I spoke to the GM to offer feedback and suggestions on how to improve. In addition to a small bit of compensation (which I didn't ask for), he offered to call the GMs of my upcoming stays to warn them of me / upgrade me as a favor to him. In my current hotel they upgraded me to the second biggest room in the hotel and gave me a platinum welcome present & hand written note, despite being only Gold.

Will be Platinum next month though