My experience is a little different with the upgrades. If you book a "moderate" room (this would be an interior view room in San Francisco, or a garden view room in Barbados*) you will be upgraded for free to the standard Fairmont room unless the hotel is sold out. I believe it even states this on the reservation.
Other than that I think Presidents Circle anything will get you the nicest room the the category you booked over the none PC members. My second stay ever at a Fairmont was in Singapore and I had a nice view of Marina Bay, but an otherwise normal room. I was pretty impressed with the PC dedicated check in, free wifi and a nice view for someone who was just a "member".
The Fairmont bed is the same in all the rooms, and for most hotel stays, that is probably the most important thing for me, and the base rooms are nice. Maybe I am just easy to please.
* Glad that one worked out, or I would probably be divorced right now.