We were on the PG in October of this year. We did 1 dive thru them on Raiatai (it was a night dive on a wreck, and it was fantastic!) There were only 4 of us and 2 DM, which was great. They did use an outside operator, but one of the guys from the ship came with us. We also did a few dives with TopDive in Moorea (we did the pre-cruise hotel stay,) and bought a package so that when we were in Bora Bora we went with them instead of the ship. Laurent (head of the dive dept., very knowledgable and quite funny) was sort of bummed that we weren't going with them. We spoke with people who did day dives with the ship, and they liked the convenience of going off the marine platform in a Zodiac, instead of having to go to shore to meet the other dive operators. We didn't find it to be much of an inconvenience, as we wanted to go to shore anyway.
Doing an early dive with the ship would be a great idea if possible, because then you meet the other scuba folks. We ended up meeting some great people, and are doing our first live aboard in August, with a couple we met on the PG.
We brought our own wetsuits, masks & dive computers. Rest of the gear was from the dive operators, and it was fine. They were great at switching our dive computers on & off for us.
Have fun!