I have his Scriabin Concerto, It's excellent, stands up to Ashekenazy.Your observations about his rubato and tone are borne out in this recording. Have his Medtner 3rd Concerto and Sonata Tragique and Sonata op.22 on vinyl, my first Medtner I ever heard. There's some harsh tone and mushy passagework particularly in the Tragique but the temperment is excellent...have you examined this guy's discography? He's recorded huge segments of the standard literature,mostly for Vox Turnabout in the 1970's and 80's, including complete Schumann. My grad school teacher, who knew/knows him, called him "a music eater", one of those people with phenomenal memory and a big technique, enabling him to devour large parts of the literatre in the time most of us take to learn a single program. Never heard any of his Scriabin except for the Concerto.
Wonder what he's doing nowadays, haven't heard anything about him in a long time.....