Karajan conducts with his trademark smoothness, which works well with the soaring strings in these pieces. But, his lack of edge and attack results in a lack of excitement and involvement. For me, this condemns these recordings to background listening. Jochum, Solti (boxed), and Abbado had better success.
Sonically, the Brahms seems compressed for a DG recording, which results in a lack of depth. Worse yet, the orchestra was recorded with microphones separated too far apart so instruments appear on the far right or far left. This was a technique of early stereo to impress the listener with the extreme separation, and to contrast it with monophonic recordings; however, it is distracting and not realistic. The DG engineers did better with the Schumann (recorded 8 years later), which sounds more blended and natural, and opens up with more depth and detail.
No one seems to want to agree with the main editorial review, probably because these performances are not abysmal. However, there are better performances available, and certainly better engineered recordings.