The Evason's charm is due to its seclusion, natural surroundings (they didn't clear-cut all the trees in sight to plant uniform and occasional palms, unlike some places!), and million dollar views of the Andaman Sea. They have a lovely private island you can reach by free long-tail boat off the resort pier. The spa is great, there are plenty of good food choices, and the staff are personable and efficient.
Reviews I've read online chide the hotel for a lack of elevators. It is a sprawling property with plenty of outdoor corridors and walkways and paths. There is a continuously running tram to get you from one end of the resort to the other if you decide not to walk. Yet, some travelers persist in complaining. (I would suggest if you are out of shape and impatient, you stay somewhere else, b/c you will be miserable here.)
The three pools are all nice--the family pool is the least attractive, but it's a good few degrees cooler than the other two--and the fitness facilities are good.
My only complaint: hiring a resort car and driver requires a minimum 3-hour booking and none of them seem to know the area very well! Bring your maps and guidebooks--the driver will need them! (Or you can walk off resort and just flag a local cabbie. Or look for a sign--many food stalls will also advertise cabs. We did that and had much better results.) Also, confirm the price--they may try to change them on you.