Am I wrong, or have the Amazonians hashed up the reviews here? Supposedly they have to do with the Muti-La Scala DVD of the Dialogues, but in fact they seem to be talking about the Opera du Rhin (Strasbourg) version. The latter seems to get 4-5 stars and perhaps La Scala does, though it's hard to to tell.
So while I would probably agree about the performances of this wonderful piece, I would give Amazon one star for messing up. (It's a little bit like a recent experience I had with Spotify, when clicking on what was allegedly a new recording of Beethoven's Kreutzer sonata brought up instead the last act of Don Giovanni).