I have heard many versions of Tristan & Isolde, including Karajan's 70's version (also on EMI), Bohm's, Barenboims etc. But this recording is in a different league. It is the emotional involvement that sells it for me. These are superb artists and to add to their superlative vocal ability they truly inhabit their characters.
Flagstad has an emotional vulnerability in her vocal portrayal that gives her the clear edge in characterisation over Nilsson in the Bohm recording. Flagstad also has more tonal beauty. But I must give a word to Suthaus. He is underrated. I agree with Furtwangler. He had a very high opinion of Suthaus. Suthaus is excellent. I certainly prefer him to Melchior, (in the historical 30's recording), especially in Act III, where Melchior's emotional histrionics claim far too much attention from the musical experience as a whole.
It may be a mono recording, (a fine one indeed),but it leaves the other stereo/digital recordings standing. A legendary set. Buy it. Hearing this performance is a genuine priviledge. Thank you all concerned.