A few tips...
1. Do not stay in the deluxe rooms at the top of the resort, they are miles away from everything (not in a good way). If you are going for the cheaper option book into a pond room. If you can afford it, the ocean villas are gorgeous. We changed to a pond room upon arrival because we had no desire to stay so far away from everything, plus rooms on top of hill (in another time zone) were not great. Pond rooms were nice, clean and modern.
2. Pool is great and we had several nice lunches in pool bar.
3. It is great to be able to snorkel in front of hotel. It is not great snorkeling, but for those who love it, it is nice to be able to do it at hotel which is rare along the Lanta coast. Hotel provides equipment. Ocean pool, whilst not amazing, is fun. Also great place to sit and watch sunset.
4. Breakfast is ok, not nearly as good as other places we stayed on our trip, but good choice and never left hungry.
5. Never ate in restaurants in evening. We considered them to be of questionable quality, always empty and over priced. Check out the cooking schools for some great food (Time for Lime and Roi Thai), both have great food and amazing atmosphere by sea which you will not get at Rawi Warin. Time for Lime is a little farther away but tuk tuk is 400ish baht, Roi Thai you can walk down the beach or take a very short tuk tuk ride, such an amazing relaxed atmosphere.
6. Tuk tuks are always just outside the hotel to take you wherever and good value. Also 7-11 for poolside snacks/drinks just out the gate of hotel.
7. We booked a sale package at the spa and it was really nice. They have treatment rooms with private steam room, jacuzzi and treatment rooms. Very lovely staff. Also good massages on beach just to left of resort for cheap.
8. You can have all your laundry done for cheap just out front of hotel. Quick, good service.
9. Transfers to onward destinations can be booked across the road from hotel at travel agent. This was easier and cheaper than trying to get hotel to do it.
10. The movie room and movie rental place never seemed to be open nor was there ever an attendant.
11. Service was sometimes slow but not dreadful. I would not recommend attempting to get room service. There seems to be something wrong with the management or staffing. This hotel has a beautiful location and facilities, but it does not seem like it is being utilized properly. If they could get their act together it could be amazing.
12. There always seemed to be plenty of lounge chairs unlike some resorts.
Overall we enjoyed our stay on Lanta. We spent a lot of time doing things away from the Rawi Warin (cooking school, diving, shopping and eating out). Days by the pool were nice, but if you are looking to go to a resort where you don't leave and eat all meals at, this might not be the place. If you dive, you must use Dive and Relax, they are the best dive operation, bar none!