I just bought this 13-disc set for $40. It is comprised of famous Mahler and Bruckner recordings conducted by Bruno Walter. I think 1, 2, 4, 5, 9, DLvdE are in the set. I also got Solti conducting Salome and Arabella and Furtwangler's Tristan with Flagstad. I was curious if Klemperer's M9 is worth getting?