I will focus on the ten greatest quartets (#s 14-23) which I know best. However, the QI play the earlier quartets just as well. Occasionally the QI played too slowly for me, especially late in its career. But in the Mozart I found little of this problem, which allwos one to enjoy their beautiful sound (individually and collectively) and savor the depth -charged interpretations-sound was a factor but rarely an end in itself. Tempi here are usually played as written, not too slowly but not rushed (c.f their slowish Beethoven opus 18s and theirSchubert #15) There is not a weak interpretation here, an asset which parallels their Beethoven #s 7-16 and Schubert #s 12-14. The music itself is glorious and it is shameful that @s 20-23 are ( or were) less well known. I would renk them as follows in descending order: 15, 23, 22, 20, 21, 19, 17, 18, 14, 16.Peers: Emerson (especially #s 21-23-they did not do #20), Smetana, Amadeus, Guarneri