I've done both. Although both get a lot of tourism IMO the Caribbean is too tourist centric. If you can get away from Tahiti and Bora Bora, to some of the other islands tourists are fewer and the people are friendlier. Not knowing the itinerary of this charter I would have to say the Marquesas and the Tuamotus are the ideal places in French Polynesia but they are even harder to get to to get on the boat - easier to get to the boat before the 3,000+ mile hop. Leaving the Tahitian group and moving on to the Cooks and Vava'u group of Tonga are great destinations.

One BIG difference between Caribbean and S. Pacific, especially French Polynesia is sticker shock and availability. Prices in S. Pacific are much higher and you will not see the American brands that you are used to.