In my experience, Amanjena has improved since 2006, but I do agree about the hammam - it is useless. They set up a couple of spa rooms in one of the pavilions, which worked quite well, but until they commit to building their proper spa (which has been mooted for a few years now), the resort will not be 100% perfect.
Of course Aman are not very good at spas generally. I don't think Adrian Zecha gets the concept!