only worth it if your rich with tons of bags then and don't mind waiting 30mins in your room
someone should do a social experiment smart casual vs stupidly expensive suit guy and see who gets the best service
Already done by me...
Be young in London and go to expensive shops/restaurants and you'll be followed around in shops and ignored in restaurants. Wear a good suit and they will leave you alone in shops and spend their time trying to attend to every thing you need in a restaurant.

It makes a massive difference in my experience and I presume many others.