There may be the individual recording made by others - Gilels, Rubinstein, Arrau - of a particular piece which might be preferred but as a collection of the Brahms piano works, this set has to take the prize.
The quality of original recording is high and the digital transfer seemingly well done. One has to listen very attentively to detect which of the four Ballades were recorded monaurally; a strange anachronism in the 'sixties. Also, the piano is an unusually fine-sounding instrument and I wonder if it might not be the Bösendorfer which resided in Decca's Hampstead studios around the time these recordings were made.
As another reviewer has suggested, the accompanying notes in french and german do provide interestingly different perspectives. But what I find inexcusable is that neither of these, nor the text in english, offers any biographical or other information on the pianist. The title is "Brahms, Works for Solo Piano. Julius Katchen". That's it - Katchen dismissed! Despite there being two blank pages in the accompanying booklet and two more of irrelevant other releases by London, that is the only mention made anywhere of the artist. I find this not only irritating but offensive.
Julius Katchen was an American pianist who moved to post-War Paris at the age of twenty. He was the consummate musician with a broad performing repertoire; a very highly regarded soloist in his time - a time which included Rubinstein, Backhaus, Gilels, Horowitz, Moiseiwitsch and Solomon - and a very empathetic accompanist but whose achievements like those of Witold Malcuzynski are not so well remembered today. This set serves to redress the balance a little and introduce Katchen to a new generation who surely will appreciate what in my view is the best available recording of the fiendishly difficult Paganini variations. His recording of the Brahms Opus 24 Handel variations (which are up there with Bach's Goldbergs for sheer breadth of musical invention) also is one of the best.
I recommend this set very highly.
As an unconnected aside, some fifty years ago and quite by chance, I found myself sitting next to Katchen on an aircraft. I remember he had unusually expressive hands; a useful attribute as the noise level of the DC3 cabin militated against easy conversation! At the time, I was wrestling with the G minor Rhapsody and he was very generous with his advice (and a free ticket to a recital the following evening!). A charming man who died prematurely in 1969.
Buy this set - I can't imagine why you would regret it.