I did this one in Oct 1998 on the Crown and rate it it the top two or three out of my 16 cruises. Would do it again in a second if given the chance.
If you can either before or after the cruise spend some time in Tahiti, or more specifically on Moorea. Gorgeous island and easily reached by the local ferry. I spent 4 days here prior to my cruise and really was relaxed by the time I boarded the ship
The 4x4 tour on Bora Bora was great and I really enjoyed the short stop at Christmas Island. Be prepared as there is absolutely nothing here as far as facilities, just the Pacific as you imagined it.
Enjoy the trip.