An interesting discussion. I have successfully used all or almost all SNA since SPG began offering them several years ago. Not always in my first choice ( although I knew that an 8 day request at the Moana Surfrider in February were as well as 8 nights at the St Regis Rome were long shots
). This year all 10 have been declined every single time I have tried to use them, so for the first time ever I have been unable to use any. That being said, one of the three hotels where they were declined upgraded me into the same category of suite without the SNA ( which used to happen with SPG too IME ). When I tried to apply them at a fourth after they were returned to my account I was unable to do so, although they upgraded me to a great Executive suite anyway.
Of the two that upgraded me without suites 1 was legacy SPG ( Sheraton Mirage Port Douglas Australia for 6 nights) , the other legacy Marriott (Surfer's Paradise Resort 3 nights). Of those that declined and didn't UG to a suite one was legacy Marriott ( 2 nights Brisbane) and the other a brand new Westin ( 2 nights also Brisbane). The Marriott UG to what was the best available room type, the Westin far from it ( but that's a whole different post).
Ironically, while I was originally concerned about the demise of the SNA ( as I typically stay 60 - 65 nights only and have no credit card options being Canadian) my experience this year leads me to believe that I might be just as well off without them moving forward.