I disagree profoundly with those who call this performance turgid or plodding; there is a momentum and grandeur in Klemperer's interpretation which carries the listener on an inexorable wave of sound. Direct comparison between Klemperer and, say, Harnoncourt, reveal, for all the latter's lightness of touch, that it is not so much a question of tempi which separates them as that of phrasing and emphases. (However, I must here observe that as Harnoncourt gets through the first movement with the repeat in the same time it takes Klemperer to do so without, either Harnoncourt is insanely fast or Klemperer really is taking his time - but, for me, both performances work supremely well and simply point to the latitude a great conductor has in interpreting Beethoven - especially given the unreliability of the composer's metronome markings.) Klemperer certainly avoids the worst excesses of his later mannerisms by keeping everything moving despite the solidity of the punched-out accents. Both the outer movements build to electrifying climaxes.
I consider this to be great recording in that it succeeds triumphantly in convincing us that this is one very convincing way of performing the "Eroica" - but obviously not the only way. It is, if you like, an essential supplement (if that's not an oxymoron) to a fleeter, sharper, more "classical" approach such as Harnoncourt's - and in certain moods, I feel it's my preferred way.
I am not so thrilled by the two "Leonora" overtures; they are enjoyable, if less finely detailed accounts - but you buy this disc primarily for the inimitable Third. My four stars are a recognition of the fact that the sound is clean, slightly boxy mono, with a little distortion at the loudest points.