I have stayed at both, and the Polynesian rooms do seem noticeably larger. The ones in the older buildings seem maybe 25% larger, and the ones in the newer buildings, Tokelau, Tahiti, and Rapa Nui, are even larger than that, about 450 sq. ft., and they are absolutely humongous. I was alone in one of those, and I felt like I was wasting space. Those seem about 50% larger than a BC room. I don't know if the percentages are accurate, but that's how it seems. I don't think 381 sounds right for a BC room, I thought they were smaller than that, around 360.