I have stayed at many different types of accommodation in Sydney, from budget to apartments and many 5 star hotels. The sheraton on the park is my Favourite of them all.
The interior is stunning from the lobby to the rooms. It has a cosiness about it even though the rooms are massive and the bathrooms are extravagant. I loved the "frames" decor above the bedhead. There is a lounge, desk and lots of storage space- and this is in a normal room!! The black marble bathrooms are amazing, it gives that special touch I haven't felt at any other hotel which all feature the same modern white/cream bathrooms. Loved the separate bath and shower too.
Breakfast was great- had everything you'd expect and lovely view of Hyde park.
The location is good, quiet next to the park but close enough (2 blocks) to Pitt street mall where there is many shops at all price range, miu miu, Zara, sportsgirl etc. You can also walk 15 min to darling harbour where I'd recommend you eat at a restaurant overlooking the water. Also the hotel is opposite the st James train station for quick access to the airport or 1 stop to circular quay :)