I bought this on a whim as I love the piece and didn't know the recording other than by repute. It is the one made at the 1963 re-opening of the Munich State Theatre.
It's a really good buy. Yes, the orchestra is a little behind the singers who are favoured in this 'live' recording but that 'live' quality creates an energy and commitment that sweeps you along - Keilberth is certainly no slouch, although he allows some some exquisitely refined solo playing by the violin before the Empress Act 111 Scena. There are some pretty severe cuts I believe (I'm working without a score but even I noticed that the end of the opera is severly curtailed and I noticed other passages, such as the Solomon passage, to be missing) which will probably offend the purist more than the general listener. Even so the performance runs to over three hours.
I grew up on Inge Borkh's Turandot so it is an especial thrill to hear here in a core Strauss role here. She rises effortlessly to the terrifying demands of this role on a solid core of silvery, thrillingly projected sound and catches a terrific range of moods too. It's an over-worked adjective, but "stunning" comes to mind. Opposite her, Dietrich Fischer-Dieskau sings with sensitivity and beauty as Barak, with all the inherent simple nobility of this lovely character, the only one in the piece to have a name rather than a character description.
Those Wagnerian veterans Martha Mödl and Hans Hotter aren't easy on the ear as The Nurse and Spirit Messenger (indeed, much of Mödl's singing especially on high is really ugly) but there's authority and projection of text to spare.
Neither Ingrid Bjoner nor Jess Thomas has a voice of ideal quality, she is inclined to unsteadiness, he to bleakness of tone, but they have authority and commitment as well as the necessary stamina to confront the murderous tessitura.
I'm sure there are greater audio thrills out there and, if you haven't heard her, do try to hear Leonie Rysanek as the Empress especially in one of her 1950's performances before the tone became too thick as she had a rare identification with this role, but anyone wanting to get to know the work could do a lot worse than this (as long as they can track down a libretto elsewhere) whilst for the lover of historical performances there is much to enjoy too.
Above all, the majesty and thrill of Strauss' and von Hofmannstahl's most elaborate project comes across very clearly.