The JW is a very nice hotel - physically. It is well maintained, beautiful pool area, and nice clean rooms. Only downside is the beach which is pretty poor compared to Playa Avallanos just up the coast a few hundred feet.
The service on the other hand is lacking. During our stay we were delayed in checking in, didn't have our room cleaned one day, and had numerous incidents of not having the correct items brought to our room, or cleaned sufficiently.
The hotel looks like a JW, but is run worse than a courtyard.
I would also avoid eating at the restaurants at the hotel - overpriced (including a fee if you don't order wine/cocktails) and only average quality. There are a number of better places (Lola's for lunch, Deveena for dinner, Bamboo Sushi Club in Tamarindo) very close by.

This JW Marriott is wonderful. The pool is the largest in Central America. The restaurants and bars are very nice as well. During our stay a Boa COnstrictor was found while we were at the pool. Very Exciting! The two issues i had with the resort was the bumpy roads getting there, (Costa Rica needs some infrastructure improvements) and the beach which had rocks jutting out of the sand. Until they get better roads i will not be going back to this resort.

We stayed here for five days and loved every minute of it! Our room had a perfect ocean view, I loved taking a bubble bath while watching the waves break on the beach. Food was outstanding, spa was heavenly, service couldn't have been better. It's not exactly near town but not a bad taxi ride either or arrange tours through the hotel.

This hotel is lovely. It is very expensive. The food was very good as was the service. The rooms were very well appointed with JWMarriott standards, but felt we could have been anywhere in the world. If you are looking for '5 star American conveniences' this hotel has it. You could be in Hawaii or the mainland with the exception of the architecture. If you are looking for a cultural experience - look for a local hotel close in to a town. The beach at this hotel was not really swimmable as there were many rocks to navigate and the ocean is not as nice as Hawaii. So if you are looking to just sit in the sun; do nothing else and get waited on this could be a good get away for you. If you are looking to do something at night or absorb culture - look further.