You make many good points. 70% was a bit extreme on my end... I really only meant about half that. In any case, some of which I consider to be unacceptably paced are the second mvt. of No. 13, where it is specifically marked allegro molto e vivace, but he achieves, at best, moderato. The rondo allegretto of No. 11, the whole of Waldstein, the last movement of the Tempest which is a good example of being 'almost' there, but in the end just feels to drag, and the last mvt. of Pathetique which seems not to be a tempo issue, but an issue of overall energy. Those are just some examples among others. I have his whole collection, and that being said, I take back some of my first comments especially the part about him 'slaughtering' the sonatas. There are many which I think are exceptionally well-done (Hammerklavier, Pathetique first and second mvts., Appassionata), but as a whole, and with other pieces I've heard, for my personal taste it seems as though he is overcompensating "artsy-ness" without realizing that he's sacrificing much more, even if he does achieve a unique sound.
In addition, I can't speak from seeing him live, so I guess I must further hold my tongue. That is all.