Having not been there I can only base my opinion on the reviews I am reading.
I have read a few reviews of people who have stayed at some of the limited locations nearby and while they loved it, do tend to say it can be crowded when "daytrippers" come for the day.
I am wondering if this "crowded" is a relative word. I have booked my trip there with the intention of just relaxing for a few days in amongst an otherwise busy trip. The appeal of Phu Quoc was that isolated/less developed feeling.
I am considering staying in one of the limited locations on Sao Beach. For all its beauty is Sao Beach overly busy during the day, and for the purposes of relaxation should I stay elsewhere?