The wife and I visited Sydney over the Queen's Birthday weekend for two nights. We booked the hotel via lastminute.com (am I allowed to quote the website?) as a "mystery deal". So we did not actually know which hotel it was, beyond the fact that it cost about $160AU per night, and was 'located in the heart of the CBD, walking distance to Circular Quay'.

We were pleased to find out that it was the Radisson, after payment.
It cost us (with no traffic) about $30AU for a taxi from the airport. We were greeted by a doorman who cheerfully assisted us with our bags, without a hint of reproachment for a tip. (Besides, I had just used the last of my cash for lunch and the cab.)

We got there about 11am, but we had to leave our luggage with the concierge, since the room would not have been ready for another hour.
When we returned, our bags were already in the room.

The room itself, like the lobby, was squeky clean and looked fairly new. The room was relatively large as well, so no complaints from me about the size.
The bed was a queen size, and there were all the trimmings you would expect from a Radisson hotel: climate control, tv, minibar, desk, internet access, telephone, alarm clock, iron/board, safe, free tea/coffee, kettle, hair dryer etc.

The bathroom was well appointed with both a shower and a bathtub (separate).
The toiletries were ok as well.
As we only stayed there two nights, our room was only cleaned once, but we had no complaints about the level of cleanliness on our return in the evening.
We did not eat at the restaurant, or use room service, so we cannot comment on that.
We did visit the fitness centre though, which was well equipped with a few treadmills and exercise machines, as well as a shallow exercise swimming pool with about 4 lanes, plus a spa on the side.

My only complaint about this hotel, is the location.
Now, the hotel is located in the CBD, but you are surrounded by tall office buildings that are shut on weekends and at night, so there is a fairly lonely feel to the location.
There were no restaurants (to the best of my knowledge) within a 10 minute walking radius. Having said that, Circular Quay is just about 10 minutes walk away, where you can find a host of restaurants, the bridge, the Opera House, the ferries etc.
After visiting Darling Harbour, we think that we would prefer to stay at a hotel in this area on our next visit, since it is far more lively.
If you are a business traveller, with meetings in the CBD the following morning, then this hotel is for you. If you are a tourist, who does not mind a fair walk in a potentially lonely street at night for food, but only 10 mins walk from Circular Quay, then this hotel is also for you.

Overall, 5 stars for interior and exterior, but only 4 stars for location (due to the touristy nature of my trip).

It was all very last minute. We booked a mystery hotel on lastminute.com.au $159 and did not know what to expect. Radisson Plaza here we come!
The hotel was easy to find.We took the Airport Express Train to Circular Quay and walked 5 minutes down Pitt St. The check in staff were very friendly and professional. We were recommended an upgrade to Executive Club Rooms for an additional $35 per night. We signed up and never looked back. We scored a great quiet room on the 10th floor, away from the lifts and a very nice view indeed. The Executive Club Room was a mezzanine lounge with comfy seating, free WiFi, tea, coffee , newspapers and snacks on tap all day long. At 5pm they serve complimentary canapes and drinks. This was very pleasant surprise, full bar service including spirits, mixers, champagne, great range of wines an generous servings of canapes. All this, complimentary every evening! Buffet breakfast was served the next morning in the Club Lounge, away from the crowds downstairs and eggs made to order. I had a fantastic omelette.
Each evening, the beds were turned down, windows blinds closed, music channel turned on, ice bucket and fresh water all left by the house keeping team.
During our stay, we found all the staff to be very helpful and made us feel very welcomed. I generally stay in Sydney for business at the Jamieson Amora or Westin. Both very nice hotels but the exceptional staff at the Radisson Plaza make all the difference. I highly recommend this hotel

Stayed for a few nights for work. The staff were just lovely and the place is immaculate. Being a refurbished heritage building, Radisson have done a great job creating a lovely retro atmosphere with tasteful furniture and decor, even the staff looked the part! The concierge was a cool dude, in fact, I was surprised at how friendly the staff were, without being fake or overly-servile. Housekeeping were top notch, the rooms were cleaned beautifully. My only minor gripe was the room - I had an "atrium" room which had no balcony and a view into what looked more like a service duct rather than an atrium. It would have been nice to have known that at the time of booking. The room furnishings were really good though and you could hear a pin drop it was that quiet. The food there was lovely, would definately recommend breakfast and dinner, not expensive, and really good food. This is really the perfect hotel for a business traveller, and of course it's location in the heart of the CBD makes that even more so..

Shifted from the Quay Grand to the Radisson due to Friday night price offer ($500 at QG compared to $199 at the R.) All up a great one night stay. Reception staff very professional. Concierge always attentive at greeting guests coming and going. Room was pleasant if clearly a shift down from the QG, but view of shabby building across O'Connell st was nothing to write home about.

I think at $199 per night with restaurant breakfast (good choices) for 2 and free wi-fi included we are starting to get seriously good value. Highly recommended and would definitely stay again.