If I have a drink of scotch, then the taste sensation is objective. That is to say, I make the objective judgement that I have made a subjective judgement that I like or dislike the scotch. But in all cases, facts and preferences are perceived. With respect to the person that cannot tell, then by definition, with respect to him, they must be the same. Single perception, by itself is neither objective nor subjective.
Perception is prior to all concept of objectivity.
Since perception is relative, then the concept of objectivity MUST be relative. Your concept of 'mental sensation' is my 'single perception'. I would show elsewhere that you are both right. Beyond that sensation itself, we have a theoretic model of the world, in which a neurophysiological process gives rise to the neural correlates of consciousness. The mental sensation is not the same thing as the neural correlate.