Looked at and listened to *as a set*, the merits of this Hyperion box are much higher than "leaves no complaints". Even if the DG and Philips sets were still available (which they currently are not), they wouldn't be a threat to Hyperion's - merely competition. DG has some spectacular highlights with the Rostropovich/Serkin Cello Suites and the Italiano/Pollini Piano Quintet. But even DG has stronger performances of some of the other works in their own catalog that are not included on the compilation: The Hagen Quartett with Gérard Caussé in the String Quintets and Emil Gilels with the Amadeus Quartet (or Argerich `with friends') in the First Piano Quartet, for example. Philips has the Beaux Arts Trio, who were caught at the height of their powers and are particularly effective in the Piano Quartets with violist Walter Trampler. The Cello Sonatas with Sebok & Starker are my (emotional) favorite, anyway, and Seb'k / Grumiaux are fine in the Violin Sonatas. But the clarinet works and the String Quartets (the Quartetto Italiano on auto-pilot) are not top drawer.
The Hyperion box's less than brilliant spot (weakness would be too strong a word) is probably the disc with the Cello Sonatas. Perhaps a missed opportunity in not having been generous and thrown in Isserlis' new recording with Stephen Hough... though, in all honesty, even then I would still recommend supplementing your collection with either "Slava" or Starker. Brilliant Classics has a box out (Brilliant 99800), and it's as complete as Hyperion's. It happens to be one of the strong points of their complete Brahms box (which runs about the price of the Hyperion Chamber Works) and should not be dismissed. But Hyperion's excellent interpretations are added by extraordinary production value - not the least the exceptionally well engineered recordings that offer a continuity of great sound that Brilliant's pick-and-patch collection can't match. Differences individual tastes will inform the choice between the sets - but with at least a dozen performances that are my favorites even on individual discs, the Hyperion set is my pick among the bunch.
(You can find a more detailed review of the individual performances on this box here: [...])