A pretty impressive review that favors the St Regis Bora Bora (opened 2006) over the relatively new Conrad Bora Bora (opened 2017 after top/down renovation of Hilton) by a convincing margin:

https://frequentmiler.boardingarea.com/conrad-vs-st-regis-bora-bora/?utm_source=BoardingArea&utm_medium=BoardingArea

FWIW, the two areas where the Conrad is reviewed to be superior to the St Regis is in (1) the landscaping and (2) the rooms. But in every other area (elite benefits, best breakfast, overall F&B quality, family friendliness, beach/watersports/actitvities, and the all-important service), the St Regis won hands down.

It's worth noting that the Conrad sits on a real island hillside with tropical foliage while the St Regis sits on an islet sandbar with little natural foliage. So landscaping is natural to both.

It's also worth noting that the Conrad opened in 2017; the St Regis opened in 2006. So the St Regis rooms certainly are overdue for renovation at this point, but the biggest issues the review had with them was the bathroom layout and that sliding doors didn't always fully close. The St Regis supposedly is now closing a small number of rooms to renovate/refurbish them in the coming year or two.

Not noted was that the St Regis rooms are overall much larger on average than those at the Conrad and have much better views (since the St Regis looks right onto Bora Bora's famous Mt Otemanu and amazing lagoon while the Conrad looks out to the open ocean).

Also not noted (strangely) was the spa. The St Regis and Four Seasons are famously known for having the obvious two best spas in Bora Bora, and the St Regis spa is much larger and has more facilities (and a central lagoon). The St Regis wins here hands down, too.

This review is in pretty stark contrast to the (surprisingly negative) review by OMAAT from March 2019 (for a stay in Dec 2018):

https://onemileatatime.com/st-regis-bora-bora-review/

One wonders if OMAAT's trip in December during the rainier, hotter, and much more humid summer season had an impact on the quality of stay. Certainly, one wonders if higher holiday occupancy had an impact.