Depends what you mean by 'how big a star'. When it comes to concerts, TV/radio or any media appearances MK is well known here in the UK. When you mean asking an average person on the street: the answer would be, Mark who? Mentioning DS and a bell rings.
He can walk around in London without being recognized. He used to live just off Kings Road and I saw him a few times in the streets always wearing a hat or something and nobody bothered him at all (we used to live a mile south of him). He can live a very private life and now they have moved to
