I had the pleasure of staying at the JW Marriott earlier this year. A fantastic experience. The room is nicely furnished and the bathrooms are very very nice with a rain shower that you don't want to get out of.
The concierge loge is fantastic and the service there is amazing with the manager remembering what coffee you like and bringing it to your table in the am. The health club has great equipment and is not one of those corner room but a decent sized room with towels and bottled water.
When I go back there this is definitely where I will be staying.