I am not sure I am a normal Flyertalker. My experience with St. Regis is different. Because of $300+ Credit from centurion service, I always take account of this when I choose hyatt or Marriott. For some lower priced St. Regis, I always choose stay there if it is 2-3 nights stay.

St. Regis Beijing, Shanghai jingan, Chengdu, Shenzhen, Moscow abu khaki, lasha, Singapore, hongkong and dubai Palm fall into these category. I do not remember I did not get upgrade to suite in these locations. Service are all OK but I do not value much about it as long as I get a big suite.

I did love St. Osaka when it is lower category of SPG which made it perfect place to burn the points. Now it is total different story. In Osaka, I love intercontinental more because of it’s perfect location and bigger room.

For other higher priced St. Regis, sometimes I choose other hotels because of value.
Like St. Regis deer valley, I chose Waldorf Estonia by using annual weekend certificate or Hyatt centric by suite upgrade certificate.

St. Regis Maldives has a special value because if you redeem points you only need add $200 per night to get a two-bedrooms overwater villa, which is perfect for my family.

I stayed St. Regis New York twice but most time I choose park hyatt.

Most St. Regis are good but some are not worth it.

Normally I stay hyatt and marriott and occasionally intercontinental and Hilton.