I consider myself standing on fair ground at this moment.
While I concur with Hinton on Powell's dedication and performance, I also think that perhaps it is a little early to form a definitely, end-of-story conclusion about Sorabji's music and their performances because the music has been, up till recently, so under-exposed that the amount of scholarship being done on it is scant compared to the music and life of Chopin or Beethoven. I have many recordings of Sorabji (and many scores thanks to Hinton), by Powell, Amato, Habermann, etc., and am, at this stage, consider myself a student at it even though I tremendously enjoy every performance; I would believe no one here, save Hinton and the performers, could claim professor of Sorabji's music just yet. Powell's aesthetic integrity, pianistic power, and musical ability obviously need no defense: he is a first-rate artist and musician. While one has the liberty to choosing his preference, it does not affect the level of Powell's capability. Putting forth one's subjective opinion and packaging it as a definitive statement might seem a little insensible (for little people like me), haughty (for most), and to the truly learned, ignorant.
However, we might be missing the point here entirely. We are looking out the window at a beautiful scenary and yet we are discussing the merits of the window.