I had originally booked to go to the Centara Villas in the south of Ko Samui but I was transferred to the Centara Grand whilst the Villas underwent refurbishment. Although a bit sceptical about moving at first it was probably one of the best things that could have happened. The hotel definitely exceeded my expectations and although it is set in the busy resort of Chaweng it is an oasis of calm and serenity when inside. I had booked on a bed and breakfast option and the buffet breakfast provided was more than enough. There are plenty of small places to eat in Chaweng and the hotel provides lunch and dinner options also. Halfways through the holiday I wnet on the (free) shuttle bus to Chaweng Villas, and whilst it is certainly a lovely resort, albeit more for romantic or honeymoon couples in my opinion, it is quite remote and meal options other than the hotel restaurant would have been difficult. When booking trips and tours I found a small tour operator called 'Friendly tours' very helpful. The shop is just across the road from the hotel

We really enjoyed our stay.Not sure what I preferred, the pool villa or a delux room with ocean views. Lovely place to stay! Massage ladies out the front on the beach are great too and very cheap.

The Centara is located just over half way along Chaweng's sandy beach in a much better position than those at the northern end, which sit behind a bar resulting in shallow water. The other key difference between this and many hotels along this shore is that the hotel has a completely open vista over the sea, thereby affording all rooms sea views. The gardens are well laid out and provide shade under the palms from the sun. The pool facilities are good.
There are a variety of restaurants serving a wide range of cuisines, including Thai, European and Japanese. While we were there, we enjoyed an excellent Chinese New Year buffet held in the gardens. The staff are very pleasant and helpful.
The one reservation we had relates to the bedrooms. We had to move from our first room as it has a leaking air conditioner, which made the floor outside the bathroom extremely slippery. More importantly the rooms are in need of upgrading, with particular attention being paid to modernising the bathrooms, where colour schemes are outdated and tiling in particular requiring renovation. We understood that a programme to address this may already have been started.
This was our fifth trip to Koh Samui and this is the one hotel to which we would certainly return in future. It has the ideal combination of beach quality and facilities

Just checked into the Centara Grand Beach -- originally booked for a 6-night stay in a pool suite, and I'm planning to check out tomorrow. I was very disappointed based on the ratings and reviews on TripAdvisor, which are overly generous in my opinion. It bills itself as 5 star, and it's far from it -- very dated decor, rooms are very dark, old and musty, and just a very worn feel (think 70s/80s). Sure, you don't travel to Thailand to stay in your room, but for 4/5 star, you don't want to get depressed the moment you walk into your room.

Facilities-wise, it's nothing to write home about -- while the pool is large, it has a very awkward layout, and for a resort this large, I would expect more than one pool. Certainly doesn't give you any sense of value for money -- it's not crazy expensive, but I definitely expected a lot more for what I got. With so many hotels to choose from in Koh Samui, I think it's worth spending a few more dollars for a better vacation experience (nicer rooms, more updated facilities, free wifi for god's sake, etc).

As a point of comparison to true 4 star beach resorts in Thailand, the Sheraton Krabi (a similar size resort) is significantly better than the Centara -- updated rooms, multiple pools, nicer grounds, and an overall much more upscale feel (for anyone considering a beach vacation in Thailand, Krabi is about as scenic as they come, with world-class beaches), and it's one of the best SPG properties I've experienced.

The only positives I can offer:

- the beach is very scenic -- but then again, most of the beaches on the island are nice
- it seems well-suited for families

Didn't get a great feel for service quality, since after 20 minutes in my room and a walk around the grounds, my immediate reaction was "go find something better."

If you're like me, and do tons of research trying to find "just" the right place, it's very depressing when you immediately know you've made a big mistake. I decided to change my reservation to the Hansar Samui Resort, which seems much nicer and only for a few dollars more.