Why do some of the world’s most celebrated hotels receive lower guest ratings than others with fewer accolades? The answer lies in how excellence is defined. As Michelin’s new Key system expands globally, its view of what makes a hotel exceptional sometimes contrasts with what guests actually experience.Why do some of the world’s most celebrated hotels receive lower guest ratings than others with fewer accolades? The answer lies in how excellence is defined. As Michelin’s new Key system expands globally, its view of what makes a hotel exceptional sometimes contrasts with what guests actually experience.