I've heard many versions of Le nozze, but I didn't, like the first two reviews, find this recording bad at all. In fact, a good case can be made of it being Harnoncourt's best recording of a Da Ponte opera. The two leads, Scharinger and Bonney, are excellent, Margiono is a fine Countess, while Hampson makes a strong Count. I used to live on Giulini's and Davis's recording, but Harnoncourt does add something extra (his control of orchestral color, albeit a period one, is exemplary), and here he doesn't seem peverse enough to sacrifice enjoyment of the opera.
I find myself listening much more to the sound of the Concertgebouw as much as I do the singers. Some arias are more illuminating here than elsewhere (Figaro's aprite un po for instance). Even if this is not a traditional recommendation, admirers of Harnoncourt should find much here to savor. Non-admirers should keep a wide berth; to be fair not because Harnoncourt did not do Mozart justice, but because he illuminates other aspects of the opera.