I made a 32 day road trip traveling across the country and back starting 3 days after the new program took effect. I was PP before the new program and stayed at PP in the new program. Although there were no defined benefits for the old PP, all P’s in the old program became PP.
Here is brief summary of my check in experience for the 17 Marriott properties I stayed (or attempted to stay)
Check in by brand:

FS Marriott hotels -6

Courtyard - 3

Fairfield Inn and Suites – 3

Spring Hill Suites – 2

Renaissance -1

Residence Inn – 1

TownePlace -1

Upgrades Received as PP – 0

Welcomed as PP – 2

Welcomes as P – 13

No Acknowledgement of Status -2

$10 Voucher at FS Marriott’s Offered without asking)– 1

Bed Type NOT honored – 2 (told this is no longer a benefit)

Market Place Item at Non FS Marriott – 8 (3 say no longer a benefit)

Breakfast in restaurant at FS Marriott when lounge closed - 3 of 5 (2 say no longer a benefit)

Walked – 1 Albuquerque Marriott – Sent to a Holiday Inn Express

ALL Properties on this trip no longer provide "Enhanced" internet speed. There's no log in anymore so everyone gets the same slow unusable speed. Another benefit "Enhanced".

With the constant devaluation of Points and now reduced benefits and the fact that I am LT PP, I see very little incentive to choose Marriott properties as a first choice . I had 217 nights last year and 125 this year to date. I’m sure Hilton and Hyatt will all have thier down side also, but I will now stay at the best rate and location without regard to brand, It seems that none of the chains are too concerned with loyalty. At 80% occupancy they don’t need to worry about loyalty, but when the economy turns again, I think they may realize some of the errors they have made with the “Enhancements”.

In terms of your "upgrades" (assuming only FS Mar and Ren as options) - did you get any deluxe / corner rooms or the like, or are you counting only something like a jr. suite and above (which is what I would do personally)?

Nope. Just standard rooms. No comer rooms, No lounge floor rooms. 2 Queens when king requested. In FI and RI, was given studios when 1BR were available online. When I asked why they were available online was told not available as upgrade.

The result would be much different if you have stayed all those nights across APAC countries. If majority of my stays are in US probably I won't chase hotel elite except free with credit cards like Aspire and kayak the cheapest rooms among the major hotel chains and make sensible decisions. Luckily at least 95% of my stays are in APAC (East and Southeast Asia) and most of those hotels are so superior, even very occasionally you don't get meaningful upgrade you still enjoy other excellent benefits like great lounge offerings.

Did you talk to the GM and invoke the room guarantee?

So the room guarantee is no more?

Bedding type no longer a listed benefit. I did talk to the GM the morning after I was walked. I was given $200 check and told I would get 90,000 reward points. So far those have not posted.

Go reread this: https://www.marriott.com/loyalty/mem...s/guarantee.mi

Guaranteed room type still applies, as does the Guaranteed lounge access that they told you does not.

This is a shitshow. (Unsurprisingly), you're facing a large proportions of properties are just making stuff up. I have yet to get an upgrade from "particularly base base room" on a single stay since the merger and frequently hear hotels misquoting their obligations under the scheme.

Out of curiosity, was the treatment you received the same or similar to, prior to Aug 18?

I am presently travelling through Japan and South Korea and I can tell you that even here the hotels haved stopped giving upgrades. I have stayed at the same hotels a couple of times before the merger and was always upgraded, this time nada! And I don't count a different floor with the same room an upgrade

My experience has been pretty similar and I'm wondering if hotels have been given as much a hard time as we have. I've had 6 stays at Marriott brand properties since this has been going on and the attitude of staff has plummeted. Only last week a cleaner came into our Marriott room without knocking or identifying themselves and casually asked if we were leaving soon, 30 minutes later another walked in. A few weeks prior staff in a Renaissance restaurant who have always been considerate and friendly were openly complaining about working conditions, then another family walked into our room after being given our key. No one said bye like they usually did and they're practically spitted out the 'thank you for being a loyal customer' phrase.

Personally I can do without Marriott's alleged upgrades but people walking in is a deal breaker for me.