We have taken this cruise twice, when it was a 15 day itinerary, in 2006 and 2008. We are going on it again in March 2010.
Why? Because we love it. And we have never found it too long to be onboard. In fact, it always seems to be over way too soon.
The sea days going to and from Hawaii are wonderfully relaxing, but if you are into participating in activities set up by the Cruise Director's staff, you can keep quite busy.There are lots of planned activities scheduled each day. Plus the casino is open all day during the sea days, if you are into that. Princess has an onboard naturalist/historian on the Hawaii cruises, and they give daily presentations on the sea days. These are very interesting, and the venue where they are held tends to be completely filled.
The days in the ports in Hawaii are great. The number of hours in port varies from 9-11, plus the day in Honolulu is 16 hours. Plenty of time to do a tour of some of the wonderful places tourists like to see, and time left over to leisurely wander about on your own (unless you take a very long tour).
If you enjoy being on a ship, and don't mind several days in a row at sea, this is a great cruise. We can't wait to go again.
And BTW, I have cruised on the Golden, and she is a lovely ship. She recently underwent a drydock, and has been updated with several new amenities.
ps. There are a couple of other cruising websites, and one that is quite large has a Hawaii board with tons of information.