so far 49 nights out of 81 were in suites. 96% of my stays were in North America. so my suite upgrade success rate so far is 60%. this is much lower than what it used to be in the past few years ( about 90%). I believe this is because most of my travel this year was to North America while in previous years I had more stays in Europe, Asia and Middle East. I have more than 20 nights booked with Starwood before year end so will see if my success rate goes up or down by year end.