Both this album and its predecessor, Undercurrent, are so good.
Since I've been on a Jim Hall kick over the last few weeks, I've been spinning them frequently.
Oh yes, it's definitely considered one of the "classic" versions of DLvdE.
However, I'm not a big fan of Klemperer's Mahler -- so it's never really rang my bell.
But that's just me. You owe it to yourself to see if it works for you.