Yes, much of Furtwangler's Brahms is amazing, as is Walter's, and Klemperer's First and Second. But this Solti Brahms set has been unfairly maligned ever since it was released. Like this wonderful cycle, itself, the Solti/Chicago recordings of the Brahms symphonies deserve more credit than they get. All things considered, this is one of the best Brahms cycles going, especially as a budget-priced offering. Those looking to purchase an inexpensive Brahms Symphony cycle without having to buy individual discs cannot go wrong with this set. The performances are solid and not lacking in excitement, especially in thrilling moments like the final codas of the First, Second, and Fourth.
The recordings have been maligned for being too "boomy," but I disagree. I think that the full, weighty, well-rounded, bass response of these recordings is just right for Brahms, whose orchestral sound starts from the bottom, up. The fullness of these recordings gives weight and fullness to the brass, timpani, and low strings, but the "late analog" sound still has enough clarity to give plenty of crispness in climactic moments. I think that people who think these recordings are too "bass heavy," have become to used to hearing ineffectively thin recordings of Brahms symphonies: for example, while I enjoy many of Karajan's recorded performances (and his 1978 Brahms' Second might be my favorite recording of that symphony) I will concede that most of his Brahms' recordings sound too thin to give full weight to Brahms' orchestral sound. Brahms' wonderful symphonies are warm, passionate, full-blooded works, and they need well-rounded recordings to fully reveal their beauty. Furtwangler knew that Brahms' sound needed to have a firm foundation of bass, and while Solti's phrasing may not be as flexible as Furtwangler's, the orchestral sound on these recordings seems to have exactly the right depth and fullness for Brahms.
I found the depth of these recordings to be a pleasant surprise in an era when the Chicago SO's sound was known for being on the "blary" side. I don't always like Solti's recordings, but I don't think these performaces can be faulted, unless one doesn't like his observance of the exposition repeats in these symphonies. Furtwangler's Brahms is undoubtedly great but I think that most people - who haven't been listening to Brahms for 20 years - may not respond very positively to the "vintage" of his recordings, or his somewhat histrionic style.