Stayed at the IC decades ago when it opened as a Hyatt. At the time they had converted the RR station into a casino and built the hotel over it. Very central location and easy to walk to most places a tourist would want to get to and over the main suburban RR system to get to Port Adelaide and elsewhere in the immediate region. (Note the interstate RR station is now on the edge of the city.) It was typical high end international Hyatt.

I've actually booked the IC for a couple of nights next month (Ambassador weekend BOGO voucher), and will then move to the CP for another two nights (PP BOGO), so I'd also be interested in any recent reviews of both properties. If nothing appears by the time of my own visit, I will update this thread.