Chiaroscuro was recommended to us several years ago by the concierge at Le Meridian. Since then we have dined there five or six times and I've held one company event for 12 people there a couple of years ago. We have never been disappointed. Chiaroscuro is consistently worthy of its stars. The tastes are sometimes subtle, sometimes bold, but always superbly tasteful , creative and beautifully presented. For us the portions are just right. Since the last time we were here they have gone to a fix prix format with 3, 4, and 5 course choices. At first we had some negative feelings about the change but by the end of the meal thought it was just right. We both had the three course and left the restaurant well satisfied - full but not uncomfortably stuffed and with big smiles.
For us, the service level is just fine - attentive and responsive but not constantly hovering. My wife literally dreams about their imported buffalo mozzarella. But alas, they only serve it for lunch. Hearing how disappointed she was they prepared a special (and really delicious and creative) caprese salad for her and made it part of her 3 course meal. A nice and appreciated touch. We have dined at Michelin starred restaurants all over the world and are frequent visitors to San Francisco. Chiaroscuro is one of our consistent must dine spots when we come to San Francisco