The Oak is in a great location in "Thai Town" in the Sydney CBD. The apartment was a good size, clean, and everything worked. It also had a roomy balcony that faced east, and with the nice weather, we got enjoy afternoon drinks looking over the suburbs.
Check-in was easy with friendly staff, and I was pleased with the very fast lifts, something handy since our room was on the 27th floor. Despite seeming quite busy, we never had to wait more than a minute to get up or down.
The location is great. Quick access from the airport in a taxi or train. There are so many places around to eat that you are spoilt for choice. My favourite breakfast place was the Naked Duck, about 100m away from the apartment. Chat Thai is just another 50m for the best Thai food in Sydney.
There are many other great Thai , Japanese, and Chinese restaurants all within a 2 minute walk, and plenty of nice pubs for a few ales and reasonably priced steak or seafood meals. If you venture a little further down to Barangaroo area on the waterfront, I'd recommend Old Town Hong Kong for some of the best Cantonese food you'll find in Sydney.
The hotel location is great for getting around. Trains, buses, and light rail (trams) can take you anywhere you want to go. I was there for both business and pleasure and we used the public transport several times. Cheap, fast, comfortable, safe.
Overall other than the room maybe needing a coat of paint, you can't really fault the Oaks for the stay and the location!