I've heard references that the next fun experience will be when SPG hotels move off the legacy SPG reservation system into the Marriott one. I'm not sure when this will happen, but seeing how well the integration hasn't worked, I'm sure this will be the next fun nightmare.
I deliberately avoided staying in any Starriotts from early August until late Sept. In retrospect, this was a stroke of either luck or genius. Now I'm worried that I have a ton of stays at SPG starting on 9/24 until mid-Dec and I'm not confident they will have the Aug 18 problems fixed by then and it may be made worse if they migrate reservation systems during the fall.