Someone once asked me a question - Has there ever been a successful LOB in FP...to the best of my knowledge no other than the Paul Gaugin which is not a LOB but a small cruise ship with some diving offered in some ports.
I'm sure the Aqua Tiki II would consider themselves a successful FP liveaboard on the basis that they've been operating there for 16 years (according to their website). They offer only "up to 2" dives per day so how you or I would assess them is a different question, but I am sure they have loyal customers who are very happy with the programme they offer.
The Aggressor Fleet ran the Tahiti Aggressor for several years as well. That boat's departure had nothing to do with a lack of divers - I was told by the former captains that it ran at 100% capacity every week (suggesting some of the pent up demand for a 4 dive a day LOB in the region IMHO).
My take on the FP Master:
The Siren fleet has a very active marketing department. There is definitely demand for an FP liveaboard - lots of liveaboard divers worldwide, lots of people who want to dive a "new" destination by liveaboard, plus those who already love FP who would consider a liveaboard option - and the logistics of FP mean you could cut some flights and dive more than 1 top area with a LOB as your base, as I understand the Aggressor used to. Having had one of the co-owners of the Siren Fleet on a LOB I was diving for a few days, I have my own theory about a further reason he would want to launch a LOB there, but that's neither here nor there.
I believe the dive shops have booked it because they have anticipated the demand from their customers, especially given the lack of any other 4 dive LOB options there, and because they can make a profit by filling an entire week at rack rates (the shops keep the discounts) and/or get free berths for their staff or owners - no crime in that. A bit of googling can turn up some of the dive shops that have booked the boat. It's always possible some of these shops will not fill enough places and will release berths back to the operators. But as long as they do so before the penalties start, they can still earn money or free berths on half boat charters much of the time.
Now will the FP Master dive French Polynesia
well? I'm completely with you two on that - I will wait for the independent reports from very experienced divers. And even then, I have experienced LOBs where the cruise director was off work that week, where the cruise director was brand new, where the best DM was off that week and a weak one was working in his place, where the cook or DM just quit, etc. etc. -- lots of factors beyond the general reputation of the boat (and all completely unrelated to nature) can impact whether you experience great diving even on a liveaboard with a consistently good reputation.
My 2 PSI.