I was there both in January and March of this year. Basically the reviews above are still accurate. As a diamond you'll get the coupons for AuBon Pain, I seem to recall getting both a free breakfast coupon and a $5 coupon. I also noted during the March stay that they seemed to be trying out a new breakfast buffet, but I had no time to check it out and just grabed something from Au Bon.
I saw no upgrades either time, despite a few suites being available before checkin (but of course that's not a diamond guarentee). Otherwise the room was decent, but nothing spectacular to write home about either. Staff seemed friendly enough at checkin/checkout. And the lobby bar is open each night, should you want a nightcap.