I have never had these problems with SPG. they have plenty of properties, upgrade if rooms available, although, for a late arrival/early departure, the benefit of an included breakfast, wifi = all other benefits are more value to me.
I did lose my Ambassador benefit recently, but have just had this reinstated, with even more enhanced benefits. Whether this can be sustained going forward, I do not know.
For the record, I am currently a mere 40 – 60 SPG night per year guest, but I do refer other guests (aircrew / passengers / colleagues) into SPG properties.