I just returned on Saturday from a long trip that included 5 nights (paid) at CKS for our honeymoon. Sheirwein was amazing and added little touches across the board that made it a really special trip. I booked and paid for the stay prior to getting Diamond so I booked an Oceanview Villa outright and received no upgrade. We were placed in 310 which we really enjoyed with an unobstructed view, although the pool for 309 could easily see into our patio and vice versa. We enjoyed the proximity to Zest and the Lounge and walked down the hill (and a few times back up) to breakfast daily and it was a quick jaunt down to the pool and Azure or up the hill to the spa. Really anything in the 307 - 313 is pretty ideal if you want to walk to some of the amenities without being completely drenched in sweat and don't mind a little bit of a hill walk. 310 could use a little TLC in the shower (noted in post-trip survey) but it wasn't anything that made me want to request a change of rooms. The old library area under the lounge/Zest is currently being renovated to house the future (bigger) fitness center. That would make it a bit more accessible to the higher up villas. They will eventually convert the current fitness center to a larger kids club. We ate at Zest quite a few times but only once for dinner, when we went to their "curry experience" (I don't remember the exact title they gave it). We got to select a few types of curry, a few types of meat and 7 sides for a pretty epic spread. We were supposed to eat at Jahn as well, but my wife was ill that evening so we cancelled. Our last night we did the sunset dinner at The Cellar. That was an intimate dinner with just us and a server with a prix fix menu that was also amazing. All in all the resort was fantastic and the staff were top notch.
We used Mr. Samui to and from the airport (2000THB) and even recruited him to take us to the Lamai Sunday Night Market. We could have used the hotel shuttle for the market but it left the hotel at 5pm and left the Tesco near the market at 6 or 630 so we wouldn't have had much time to wander around. Its roughly a 20-25min drive to Lamai from the hotel. In the end Mr Samui charged 1400THB for the market trip, well worth it my opinion. If you want to see the Night Market, go there around 5 or 530 and its slightly less crowded. By the time it got to be 630/7 it was packed and it was hard to walk around. Give yourself 90 minutes to shop and eat and that should be good.
We also did excursions to Tamarind Springs Spa and InFusion cooking class, both were fantastic and highly recommended.