Thank you for this report. As a recent guest to all but Amandari (total of 14 nights), I have fresh information about all of these resorts.
Amanusa is a good architectural hotel, but in my opinion, that is about it. We had a MAJOR negative event there that will always be remembered and was NOT dealt with by the management.
Amanwana was actually our best experience. Our bathroom was not like the ones that are shown in the pictures. It was very clean. We were in room 6 or 8. The whole jungle experience and the amazing ocean life will have you forget about the fact that you're staying in a luxury tent. I did have treatments in the open air spa and the facilities looked very nice to me. We did use the music pavillion and all seemed very updated with great sound system and pillows. I do not understand all the negative remarks.
Amanjiwo was also excellent in my opinion. Sean did make a BIG difference.