My wife and I stayed at the Westin Oct. 21st - Oct. 26th for our Honeymoon. Its a beautiful resort that is well maintained and the staff is the friendliest I have ever encountered. Its an all inclusive resort so all food and drinks are included in the price of the room per day. They have lots of options for meals with different restaurants opened each night. We came during the 'off season' or rainy season in Costa Rica but it never rained a full day we were there. We had sunshine for two days. Some rain on Wednesday and some on Thursday but overall sunshine and beautiful weather. Because it was the off season not all of the Restaurants were open every day but they rotate them each evening to give a lot of variety.
They have lots of activities that you can sign up for through the resort with a company called Swiss Travel. They have ATV tours, volcano tours, ziplining tours, jet skiing tours, lots of options. Be careful booking tours with people other than resort officials because often times they don't have permits, insurance, and aren't meeting government safety regulations on equipment.
My wife and I stayed at the Royal Beach Club. If you don't have kids this is the best place to be. The pool is beautiful they have lots of chairs, a swim up bar, and people walking around constantly bringing you drinks or food if you wish it. Its a great 'kids free area'.
The staff at the Westin is amazing. They really make your stay very special and care free. Their very accommodating, helpful and friendly. One of the concierges knew we were there on our honeymoon and as we were coming back from dinner one night asked us if we were going to be in our room. He said: "Okay I have a surprise for you" and brought us champagne and chocolate covered strawberries. (And we didn't have to pay for it)
The one downside to staying at the Westin is the beach is pretty sad. The Westin is on the Pacific side of the country and everyone over there says the prettiest beaches are on the Caribbean side of the island. The Westins beach is over run with sticks and with people trying to sell you things(which was fairly common everywhere from people we talked to staying at other hotels). The pools make up for this however, I think.
We loved our stay at the Westin and from what we could tell from talking to couples staying at other hotels it is definitely one of the better places to stay in Costa Rica. I would highly recommend coming here.