I went to Alyn Williams a couple of weeks after opening. Lovely room, very reminiscent of the Berkeley actually. Absolutely stunning service - they let us sub in any ALC dishes (including a langoustine starter) or any vegetarian tasting menu dishes into the main tasting menu. At the moment they are running what I can only assume is introductory prices, £55 for a 7-course+ tasting menu must be the best value fayn dayning in London at the moment. I was consciously not taking notes but some excellent dishes: crab, ox cheek with a cold onion consomme in a martini glass, then my girlfriend had a langoustine and apple dish while I had scallops with celeriac, oyster and caviar. Then dorset snails. A red mullet with malt and vegetables was ever so slightly undercooked but would have been the standout dish otherwise. Then the classic rib of beef sous-vided to perfection. We got an extra vegetarian gnocci dish, which was stunning and actually the highlight. Very generous cheese plate, brilliant pre-dessert of granite and custard and a seventh course I've forgotten. Overall it was a superb experience, one of those head: 9/10 heart 7/10 ones. Service flawless apart from mild upselling on the wine. The cooking is also very-nearly-almost flawless and at the price point is basically ridiculous value.