When this set was released in the mid 90s my cellist friend who was -and still is- a great Slava devotee of course didn't doubt one second before he went to buy it, since it's simply the greatest music played by the greatest cellist. When I asked my friend after a week or so how it was, he frowned bitterly and said "Avoid it for Heaven's sake! Try Heinrich Schiff instead."
As it happened I just heard the Rostropovich set today for the first time, aware of the strong, unanimous ovations from Amazon's customers. After hearing a few bars my friend's reaction sprang to my mind -he was right. I heard a great musician in serious decline. Ok there is 'wisdom' and 'authority'. But I sense a painful lack of cantabile, dance and flow. And what about purity of tone and intonation? I couldn't believe my ears; try the Prelude from the 4th Suite for a sample. Scandalous!
I'd love to be able to overlook these shortcomings as being merely technical and superficial, but I can't. The music doesn't have some kind of varnish under which the 'essence' or 'heart' lies. The music IS its surface or, the surface, the technique and their beauty are inseparable parts of the music itself.
For Bach's Cello Suites I would recommend Janos Starker on Mercury. Among Rostropovich's recordings I would recommend Schubert: Arpeggione Sonata, Concertos by Shostakovich (don't miss Nr. 2!) and of course Dvorak and finally Prokofiev's Symphony-Concerto (Sinfonia Concertante).
I know only one bad record by Miles Davis and it's Doo-Bop (one of his last if not the very last), one bad by Jascha Heifetz, namely Schubert's Fantasy and here we have Maestro Rostropovich's contribution to that category -based on what I've heard which indeed is from a limited not to say narrow horizon (at least in the case of Rostropovich).
If only he would have recorded the Suites some 15 years earlier!