I am not completely sure these performances are unassailable, but I cannot think of any more rewarding, glowingly presented version of this rather common coupling. The Alban Berg quartet plays with a security and almost visionary grasp of the structure of the works, and even though they prioritize precision over poignancy, the playing is imbued with a warmth, polished sheen and a golden hue that is almost breathtaking in its beauty. I can, perhaps, see how some listeners might prefer a slightly more overtly romantic approach to the Debussy (in Ravel the approach is beyond reproach and thoroughly idiomatic), but even those listeners should be forced to hear this more restrained version and might very possibly change their minds.
The players are, as expected, especially successful in the faster movements (in particular the scherzi and finales), but even the slow movements are wonderful - the slightly emotionally detached approach tends to create almost dreamlike, wistful atmospheres rather than plumbing any existential depth, but I don't think that is to the detriment of the musical or artistic experience. The breath of fresh air that is the Stravinsky is less of a surprise after the Alban Berg's crystalline rendition of the final movement of the Ravel than one might have expected, and they render these relatively slight pieces with a wholly appropriate freshness and crispness. The sound quality is generally wonderful if a little close. Very strongly recommended.