Both are great options. Although Six Senses may have glossier finishes, and is a newer product/property, Aman's Kerry Hill design is timeless. I feel because Amankora arrived earlier (the first) and secured some of the best pieces of land, some of their properties can not be matched. For example, nothing compares to the vantage point of Amankora Gangtey... sweeping views of the valley that'll give you chills.

Bhutan is a special destination, and if you're on the fence, I'd say take the leap and go with Amankora, this is undoubtedly one of the rare original aman experiences (my favorite of all the amans) that is certainly worth the premium.