I stopped in on my evening walk (read: I was underdressed, not gussied up for a night on the town) on an early Friday evening.  Even so, I was treated to what was - hands down - the best sushi/sashimi experience ever.  I had several dishes. Every one involved incredibly fresh fish with thoughtful use of ingredients with a beautiful presentation.  Each bite delivered often subtle but intricate play of flavors and textures.  The selection of fish was much broader than the usual good sushi restaurant.   All of the wait staff and sushi chefs I encountered were attentive and knowledgable.  And no one made me feel self-conscious that I had arrived in my jeans and walking shoes.  The atmosphere is definitely aimed at attracting the trendy upscale clientele (the W is known generally for it's bar and party scene) but serious sushi fans of all types and ages should make a point of eating here.