For about half our honeymoon, we booked the 7-day Star Flyer cruise through the Society Islands. I hesitate to say "cruise" because I am not a big fan of cruises (this was the largest boat we've travelled on, usually we do Diving liveaboards or the like). So take this feedback from the standpoint of a "cruise hater" if you will.
The boat itself is extremely nice. Again, I have not travelled on massive cruise ships but compared to "real" boats I've sailed on, this was extremely nice, large, and well maintained. It makes a good first impression when getting on-board.
The cabin we got was also quite spacious, compared to what we'd expect on a smaller liveaboard boat. It was smaller than a typical "Motel" room on land, but still felt plenty spacious for the amount of time we spent there. We got a "Category 2" which seemed to be a sweet-spot for price/value. Most rooms seem the same basic size, but the location varies. I would recommend to anyone going on-board to avoid Categories below 3, they are (from reports from others) generally too noisy or otherwise compromised. Cat 2 are on the "main" room deck. Category 1 are larger and on the top deck, but are a bit in "high traffic" areas and didn't seem worth the price bump.
Our trip was about 50% full, and most people on board had either gotten a hefty discount through a consolidator website (as we did) or cashed in on a free airfare offer from the cruise company and paid the standard rate. We were told by the crew that the next cruise out had about 110 people, which is more like 80% capcaity or so, but it seemed like the boats have been going out something like 50-75% full. IMO this is a good thing for the passengers, more staff-to-guest ratio!
The activities from the boat are a combination of sign-up sheet outings which vary from place to place and open-ended schedules of boats to-and-from the shore or beach (or both). The activities were mostly pretty active - ATVs, Shark Feeding, Kayaking, etc. Most ports they also had up to 2 dives. Even with 50% of the guests possible, activities were popular and I think groups went out diving every day it was offered. The sports crew was very friendly.
The whole crew was extremely friendly, even by FP standards. English is the primary language of the boat, followed by French and German. The sports crew for example was 75% Canadian. The bartenders were all great, very laid back and friendly, joking with the passengers. Not at all stuffy. The waiters as well.
Prices for stuff on board were actually surprisingly good! In fact when we were moored the last night in Papeete, the crew (who were very friendly with by this point) said that the cheapest place to drink that night in Papeete was... on the boat! 3.5 Euros for a Hinano is pretty fair. Tropical drinks are like 4.50 each day when they are the "drink of the day" and maybe 7 euros otherwise. Compared to Bora Bora later, it waas a HUGE bargain. Prices for outings are probably marked up a bit from what the local vendors charge, but still quite fair.
For diving, they charged 48 euros per person per dive with all equipment. Compare to our dives on Bora Bora which came out to around 75 euros per tank/dive. The dives go out directly from the boat to a local dive site via Zodiac launch. Very quick and convenient. Their dive gear is good, but could use an update.
The food was good, and varied quite a bit. Breakfasts were pretty much the same each day, with a bit of variation (just like hotels). Really the food quality was on par wih a 4-star hotel's. Lots of snacks here and there. I was a bit annoyed that they charged for sodas and bottled water, I think it would have been classier to include non-alcoholic drinks.
The average age of the passengers was definitely higher than we saw later at Bora Bora (Thalasso), but not as high as I would guess for a cruise like the Paul Gaugain. Being in our mid-30s, I would say there were 10-12 couples our age or younger, quite a few in their 40s-50s, and another groupd of 20 couples in the grey-haired years. But it was definitely not a cruise of "napkin folding lessons on he Lido deck" sort of thing.
There were moments of cruise-ship cheesiness. There was a full-time "musician" guy who did cheesy renditions of randon stuff on a Casio keyboard. It verged on a "so un-hip its hip again" sort of vibe and was tolerable. There were little evening events (most of which we skipped, usually exhausted from so much sun & beach sports). Some like the talent show were a bit hit, and aided the sense of bonding amoung passengers.
I should note here, even if you don't want to pay for beach actiities, there is a lot you can do for free. Each day either from the boat or from a nearby beach, you can Waterski, wakeboard, snorkel, Windsurf, Kayak, etc. all for nothing.
Overall, this was a great way to see a lot of different islands at a per-night rate, including food, that is significantly cheaper than hotels & restaurants on each island. Especially on Bora! We had a lot of great unstructured days, like spending all day on a quiet beach in Huahine and drinking a lot of beer and having burgers at a local beach bar with some of the crew, to doing the same Shark & Ray feeding stuff in Bora that the hotels send folks to.
There were some negatives. If you have any history of sea-sickness, this boat does move quite a bit. We had a lot of nights and even sometimes during dinner where the boat motion made a lot of people ill. Don't disregard this potental negative to your trip! Take all precautions ahead of time. Also the current schedule they are on feels a little rushed in some locations. We only really spent 10am through 4pm on Bora before the boat had to start paddling back fo Moorea. I would think the schedule could probably be improved to allow more dinners at-port.
Overall, this was a great experience for us. Unlike a hotel, you really do get a chance to make friends with the crew and other guests. We ended up trading emails with about 20 other couples and sending each other pictures from the trip. The passengers were probably 50% or more American and decidedly west-coast so there are a lot of people to chat with, and dinners/meals are setup with a mixture of social tables with up to 8 spots, or 2-spot tables if you're feeling standoffish. It was very easy to make friends and conversation.
The biggest negative is probably that the Star Flyer is only staying in this great location for another year and then heads back to Europe. According to the crew, this has less to do with the economic downturn, and more to do with escalating costs & regulations imposed by the FP government, as well as the maintenance challenges of maintaining a boat like this so far from the required parts and suppliers.
I strongly recommend folks checking this out as a great way to get the highlights of all the major Society Islands (or Tuamotus on the longer 11-day cruise) at a great cost/value. You literally can experience all the best activities on each island (Scuba, snorkling, sharks, turtles, ATVs, etc.) while still paying less than $600 per night including your food for a very nice cabin.
My only reservation would be if you are known to be susceptible to motion sickness that doesn't respond to Bonine or "the patch", don't risk 7-days of potential nausea, its a smaller boat, not a floating hotel!
Don't avoid this thinking that its too full of old people (that's somewhat true, but not to a degree that detracts) or that there won't be anything to on board for the active vacationers.