I got an epic complimentary suite upgrade at Marriott... once, 5 years ago. :D Since then... not so much. In 2018-2019 my upgrade rate was so poor even as a LT Titanium I shifted many of my stays to Hilton, where HH Gold status I get as a credit card perk gets me upgrades about as often.

I have received it a few times, more during the good old SPG days, usually at a hotel where I was already a well-known repeat customer. The most memorable one is when I was given an upgrade to Raja Suite at the SGS.

Checked in today at a Design Hotel (former SPG), we've upgraded you to a jr suite (on a points and amex and visa awards I needed to use by March). Eliminate business stays, that I don't care about but usually get some sort of upgrade, my personal travel runs at 80%+.

I'm on a trip in Europe, 1st hotel, UG'd room to suite, 2nd hotel UG to exec level (no suites showing on line), 3rd hotel, a RI, gave us a corner suite which was great, no better room showing on line, 4th hotel reward redemption ug to jr suites (and no suites at all showing on line).

My new Ambassador called the hotels and asked them to give us UG's but no commitments. And we have not recieved any 'special' welcome gifts in these says, which tells me my new Ambassador has not had a heavy hand in this (my just retired Ambassador would have had requested something at one of these properties).

Interesting reference point, we stayed one night at a Hyatt House, where I don't have top status and they did write me a personal note, left in my room upon arrival. And it was a great room, certainly more than we hoped for as a low tier elite.