Don't hire a car if you are staying here. Directly opposite Museum railway station and within walking distance to the city and Darling Harbour. Also walking distance to monorail station and bus stop half a block away.
My booking was mucked up at check in and wasn't happy with the way it was handled. It was sorted out in the end, but only after I asked several times. Once that was sorted there was no problems though.
Wouldn't rely on the continental breakfast to get you through until lunchtime either. We used it as a snack before heading down to Darling Harbour to get something more substantial.
Room was clean and great. Great view into Hyde Park. Definitely ask for a room on the Park side. Other friends didn't and had no natural light into their room at all - not a problem if you are only using it to sleep though.
Would definitely stay here again purely for the ease of location.