We stayed at the hotel in November 2012 for one night, to celebrate our anniversary. Whilst we had an enjoyable stay, we were left very underwhelmed by the experience, in light of the expensive rates charged to stay there. This is undoubtedly the most expensive hotel in Sydney, effectively charging 6-star rates, and for this price the experience should be faultless. Our main gripes were:
- We chose an Opera King room because we wanted a view of the Opera House. Unfortunately you could only see the Opera House when standing out on the balcony, not from the general room itself which we felt was a bit misleading. (The image of this room on the website also gives you the impression that you will see this view from the bedroom).
- I don't believe you should have to pay extra (about $30) for wifi access when you are paying such expensive room rates
- The hotel generally felt understaffed; attention to detail lacked on several occasions, as an example we had room service for dinner and it took an hour for our plates to be cleared; after 2 phone calls and at 10pm we ended up leaving the plates in the hallway ourselves so we could go to bed
- The breakfast buffet seems very small and limited in what it offers you, and is not at all on par with a 5-star hotel breakfast that one might expect.

Overall, a pleasant enough but very expensive night away.

I'm usually a 3-star accommodation kind of guy. But recently I travelled with a friend, and he booked us in at the Park Hyatt in Sydney. I have to say, it's an experience that I think everyone should do at least once!

It was my first time in a 5-star accommodation, so you would naturally expect that I would think it amazing. I have since stayed in others, and have to say that this one still shines. (Of course the opera house view out my window definitely helps!)

I work in hospitality, and am quite critical of service. While I mostly work in cafes and restaurants, I have in my years worked in 3, 4 and 5-star hotels, and no matter what the venue, it always comes down to the staff. During this stay (and in both other Hyatt's I have since stayed in), I found the staff exceptional. 
To name a few: Christian, Patrick & Rebecca were great at concierge, and Alex, the night manager, was also very helpful.

If you can afford it, or even if you can almost afford it, I highly recommend a stay here.
If you can't afford it, make a few sacrifices, work a little harder, and then treat yourself. You won't regret it!

This is the best hotel I have visited in Australia. Incredible views,
exceptional service from staff, unbelievable location. Stayed in a
wonderfully spacious room which had incredible views of the Opera
House and two balconies - on Saturday nights there are fireworks
beside the Opera House. Rooms very modern, clean, spacious,
with everything you could require. Very impressive and worth the
cost for the experience.

Perhaps the best service and staff of any hotel I have been to:

Pros:
Amazing location. Many of the rooms have the best view in Sydney.
Extremely courteous staff
Rooftop pool
Very large rooms, with tons of features (SmartToilets, lighting, great bathrooms, large bed).
Heated pool, cabana seating.

Cons:
Some rooms long walk from stairs/elevator
No rooftop observation area. The Sydney suite gets the view, not the pool area.

Overall, this was an amazing hotel.