I stayed at the Sydney Four Seasons last August. I booked an Opera junior suite, which was spacious and had a nice view. I thought the decor and furnishings were a little dated (old tube TVs, tired looking sofa), but everything was clean and in decent condition. Bathroom was large, with separate tub/shower and toilet in its own little closed off area. I understand the standard rooms are a bit on the small side, so I would reserve a higher category if you want space. I didn't eat in any of the restaurants. The fitness center was well equiped and useful. I liked the hotel's location ... near the Opera House, public transportation, and ferry docks.
I agree with other people's opinions about the service ... it is not as good as I've experienced at other FS. It certainly wasn't bad, and I didn't have any unpleasant experiences. But none of the true (or at least very well simulated

) warmth, hospitality, and graciousness I've had the pleasure of receiving at other FS hotels.