There are a bunch of mentions of the JW in prior posts, but I just finished a stay there last week and will echo what those posts say ...
It's a top-notch hotel, from the rooms to the service to the views. Even the bathrooms are top-of-the-line. Easily my favorite Marriott property. Great lounge, too, with the world's highest library on the 60th floor (check out the hidden door). A bunch of solid places to eat are within walking distance, as well. You'll enjoy the stay - I could use another few nights there.