I'd give this CD 3,5 stars (if that option was available). In short, the performances are good (not great in my view) and the works themselves are all brilliant compositions with the exception of Beethoven's octet (his septet which is also on this CD is a wonderful masterpiece).
I am entirely satisfied, however, with the sound quality on this set. It is by no means poor but the accoustics are a bit thin for my taste. Having said that, the violins never sound scratchy despite this and each group of instruments is easily recognisable (the sound is clear enough, just not rich enough).
One certainly gets what one is paying for: very satisfactory performances of great works in a clear, albeit not rich, sound.