My understanding is this property will basically upgrade to Studio Suites if available but is reluctant to upgrade above this. The rate they charge for Studio Suites is pretty reasonable (slightly more than a Cool Corner Room) therefore they are frequently fully booked just like SGS suites or given out already to other status guests. I'm not sure if they prioritize by level within upgrade eligible guests or not (i.e. not sure if Ambassador is more likely to get one than Titanium than Platinum). Given how much I like the room, I typically just book a Studio Suite these days and have done with it.
My upgrade record is not great here either despite quite a few stays (less than EGW1, though). Back next weekend again and will report back. I wonder if they lost some data in the SPG change over like St. Regis did.