The PCC is by the North Shore. If you think of Oahu like a clock, the PCC would be between 1:00 & 2:00. I did the PCC has a teenager (many moons ago!) and have not returned. But, if you are very interested in Polynesian culture and don't mind paying the high cost, you might enjoy it. The PCC alone would be a full day including the drive to and from Honolulu.
Personally, I would rather rent a car and drive around the island independent of a tour group and spend as much or little time desired at the various locations. We spent around an hour at the Temple and enjoyed the serenity. We also stopped for lunch at Turtle Bay and, being in October, we were fortunate to see some large waves at Waimea. You probably won't see large waves at this time of the year and that may make the North Shore a bit disappointing.
We also hiked to the top of Diamond Head and went to the Bishop Museum. I feel the Bishop Museum has as much culture on display as the PCC, but it's not interactive.
Please post your cruise comments when you return. We are scheduled to sail RT from San Diego in October 2011 and we are interested in hearing about other people's experiences. Have a great trip!