I understand the desire to eat at a WORLD-CLASS basically French restaurant -- which is what the Ramsays are -- but, I'm not so sure that I'd devote precious London time to doing it... especially with a food hub like NY so close to me.
Bibendum, which I recommended, is kind of in that mold too. The first time I ate there was on business, right after it opened, when it was the hottest of the hot places in London. Food was good. Great in fact. Service was incredible. I didn't pay. What can you say? I ate there a few more times since -- always good, always great service to the point where I let the waiter order for me. I'm not as choosy as you; my number one rule being, "If it's seafood, I like it;" number two, "If it's well prepared, I like it;" and number three, "No food too strange."
I digress. What I remember most, was eating there years later, summer of 1994. My family -- wife, son, daughter, my parents -- were in London for a week. At that age, 14, my son was not easy when it came to food. Picky, picky, picky. But, he'd developed a love of fish and chips. You'd think that would make things easy in London. But nooooooooooooo. Surprisingly, most of it is not even up to H. Salt standards -- let alone what my son, bless his spoiled little palate, was used to.
So, my Dad makes reservations at Bibendum a few weeks before we leave, because he'd heard so much about it. We go. Max, my son, orders fish and chips, which aren't on the menu. The waiter says, "The kitchen will be happy to oblige." My Dad, in solidarity, orders them as well. Sure enough, sublime fish and effing chips.
Next night, Simpsons. Same story. Fish and chips, only now my daughter's playing instead of my son because I'd built up the whole roast beef qua.joint and the silver cart thing, not to mention the history of chess and Simpsons. Fish and chips as good? Yes.