The first time I heard it I thought,'Oh dear, Klemperer is just too old to be making recordings now'. It seemed nearly like a parody.
Now, when I'm feeling more energetic, it feels like it's being pulled thru treacle.
When I'm feeling laid back, I can get into it as a valid view, all intensity and digging deep. It's a performance for rare occasions, not one I'd turn to much.
There is a movement, with a musical branch, called The Slow Movement that thinks we'd be better off if we did things lots more slowly than now. The Klemperer fits into that. With it, I find I can climb inside the work, as it were.
Ivor