Excellent, overall, I found Kovacevich'a interpretation of these sonatas generally to be superior to similiar recordings I own by Arthur Rubinstein, Alfred Brendel or Christina Ortiz. Technicaly he is second to none, but it is his artistry and interprative abilities that sets him apart. He plays these pieces more agressively and uses more contrast most pianists but he does not go so far as to distract the listener from the beauty of these pieces. The sound is generally very good for recordings made in the 1970's, however tape hiss does pop up occasionally in Op.13. Although all the pieces are very good, his interpretation of Op. 13, is the best I ever heard, However, if you want to try a lighter, less agressive Beethoven get Rubinstein's playful rendering of the E-Flat Op.31, no 3 sonata , or Brendel's Op. 111 both of which are excellent.