I suppose my question is thus: for those of you saying you almost never get suite upgrades, are you asking for them? Or are you taking whatever room they assign, hoping it's a suite?
For me, I've only had one property give me a suite without my asking, which falls in line with what many of you are reporting. However, when I check in, I politely ask while the desk agent is looking up my reservation if they have a suite available for the platinum upgrade. More than 70% of the time, I receive the suite.
For those few times where a suite is not available, and by and large the desk agents I've run into actually look in their inventory, they tell me a suite isn't available and I thank them for looking and let it go, as it is not a published benefit of the MR program.
I suppose the moral of the story is ask for a suite if you want one. If they don't have one, let it go, as it isn't part of the elite benefits anyway.