The modern pianist Lang Lang is a 'base breaker' - i.e. among the fans of classical piano he evokes extremes of both approbation and rejection. Some regard him as - either already or potentially - one of 'the greats'; others as a hyped, shallow, flashy showman.
Here is my impression, for discussion among those who care about such matters. The range of evaluation suggests a combination of significant strengths and weaknesses, and one's attitude perhaps depends on the relative valuation of these strengths and weaknesses.
His main strengths are that, technically, he seems to be able to do almost anything; and furthermore he can play with that lyrical phrasing (musicality) that is indispensable but innate (and not teachable).
His weakness is a musical equivalent of 'short-attention span'. He cannot sustain his concentration and grasp across the long spans of music that are a feature of classical music.
Consequently, his performances consist of (often) wonderful sections, each lasting some tens of seconds; but not joined together into the larger arcs of movements and whole works. Superficially, Lang Lang seems to get bored, and 'messes around' every few bars - in reality, he probably does not musically comprehend the structure of the work he is playing.
Lang Lang is like the sculptor of a bust who carves beautiful eyes, nose and mouth - but cannot assemble them into a face.
Those music critics who are able to apprehend and appreciate musical architecture therefore rate Lang Lang pretty low - while recognising the virtuosity; those who focus on the close-up musical detail (and perhaps can't grasp musical architecture, or who don't much value it), perceive that he can do this at a top-notch level, as well as anybody.
(If I am right) Lang Lang's weakness is rare among the highest level of pianists - an architectural grasp is something usually to be take for granted at that level; and the disagreement about stature is concerned with which performer's interpretation is the best exemplification of the musical architecture of a particular work.
In other words, I am saying that Lang Lang is indeed a technical virtuoso rather than a great musician; but he is a virtuoso who has genuine, original musical insights at the level of musical detail.