The Marriott Hotel Sydney proved to be the perfect hotel for me and my partner's four night stay in sydney in late Feb.
I didn't initially choose it, as we booked it through priceline.com and you don't have the option to pick your hotel.
However, this hotel is in the perfect location to see everything. It's across the street from Hyde Park, right around the corner from Oxford Street, a short walk to Darling Harbor, Pitt Street...we even walked back from Circular Quay one night.
There's also a train stop just a block away, in case you're not up for the walking all the time (also convenient to hop on to Bondi Beach!).

It's only drawback is that it's not brand new. It shows a little wear, but it's super clean, and the staff were always super friendly and nice.
Our room, even though booked on priceline.com, was on a higher floor and had a terrific view - could even see the harbor.

Oh yeah, as mentioned previously, the internet IS WAY expensive...but there's enough internet cafes around to use if you get desperate.

Just back from one night at the Sydney Marriott this past week. I generally like Marriott's so I went in with high expectations. First off, the location is perfect. Walk to the train, Darling Harbor, and Pitt street shopping. But, our first impression of the service was rough- upon pulling into the driveway, there was no bellboy to help with our bags. We waited a few minutes and I finally went in and had to ask someone from the front desk for help (they promptly came out to help us). Maybe we just caught them at a bad time but it didn't seem busy. Anyway, front desk staff was excellent and very friendly. The crib we had requested was already in our room when we got there. Room was pretty good size and the beds were super comfortable. We were on the 12th floor with a park view and couldn't hear the traffic outside at all.
Next morning we did the buffet breakfast and again, had some spotty service. The servers didn't come around too often to refill coffee and the omlet station was only staffed for 5 minutes the entire time we were there. Also, for over $20/adult (if you didn't prepay the night before, it was much more expensive) I wasn't all that impressed with the buffet. Some of the fruit was just canned pears and peaches. There were no pancakes or waffles- I know I sound picky but you try breakfast with two toddlers in tow and no pancakes.
Upon checkout, staff was again great and even offered to load up our car for us while we went for lunch. So, overall, pretty good but for the price ($330 AUD/night) I wouldn't say it was a great value.

Loved the Marriott!

What I liked:
1. Very comfortable room. Spacious, had a microwave and a sink.
2. Large bathroom .. huge bath-tub.
3. Location is good. CBD is a 5 min walk. Hyde park is across the road. Oxford Street, round the corner, has great food and drink options.
4. Service is great. I thought my camera was stolen, and I reported that to reception. They went to great lengths to investigate it. Much appreciated. I found the camera in my own bag later.
5. Complimentary chocolate, left on my bed by the house-keeper!
6. Roof-top swimming pool is awesome, with a great view.

What I disliked:
1. The room and fittings are a bit dated, though not ugly.

What I'm neutral about:
1. The gym looked alright, though I didn't use it
2. The bars & restaurants seemed fine too, but I didn't use them.

My wife and I stayed at the Marriott Hotel Sydney for two nights in late November 2007, occupying a large deluxe room with two double beds. Our room overlooked Hyde Park, and provided an excellent view. The hotel is well positioned to Hyde Park and Pitt Street, and is close to public transport, the monorail and numerous restaurants. At $171 per night (excluding breakfasts), I think that we got a good deal. Our room was exceptionally quiet, with no noise from street traffic or from other guests. Lifts arrived promptly on our floor and were never crowded. All features of our room were in good working order and were well maintained, and we particularly enjoyed the feather pillows. Our check in and check out were prompt, and staff at reception were very pleasant. We are from country Victoria and seldom visit Sydney. But should that occasion arise again, we would not hesitate to return to this hotel.