I've never to any of the Amari hotels that you mentioned. However, I have spend some times at Amari Emerald Cove on Chang Island in eastern thailand. I had a very pleasant stay. The staff was just as good as those at any international brand hotels in Thailand. While I was there during weekdays, I only see European guests that came with tour groups.

I would not hesitate to recommend any of my friends there.

regards,
drew