All 31 works that Webern gave official Opus numbers on 3 discs, conducted by Boulez (not Kolbe!), with the Juilliard Quartet and the London Symphony Orchestra, and a superb booklet with commentary and lyrics -- so why only 4 stars? My objection is the strictly chronological presentation, and the fact that I am not won over by Webern's vocal works -- I would vastly prefer grouping the music by form. Everything is brilliantly performed, and Charles Rosen, who accompanies sopranos on piano on several pieces, plays with sparkling luminosity. But the reason I sought out this collection is because I wanted to hear Boulez's versions of Webern's masterpieces, the "Symphony (Op. 21)" and "Variations for Orchestra (Op. 30)," as well as the string trios and quartets. Here these instrumental works are mixed among the lieders, Webern's many vocal works, and I find this frustrating. I prefer hearing the instrumental pieces grouped together, as on the Dohnanyi or Sinopoli discs of orchestral works (see my reviews of both), or the Schoenberg or Emerson Quartet's discs of the string trios and quartets (see my reviews of both). Unfortunately there is not a Boulez disc comparable to the Dohnanyi (on London) or Sinopoli (on Teldec). So it's either this Sony box or the several more recently recorded discs on DG, unless of course you are a total Webern fanatic and want the Ultra-Complete box with all the numbered AND un-numbered pieces...
It's really hard to fault this excellent Webern collection. Obviously if you have a more catholic appreciation of Webern's music than I (including the vocal works), my criticism is irrelevant. If you are a completist on a budget, this is a clear choice over the more expensive box. But if you are looking for an introduction to Webern's music, the best of which is some of the best of the 20th century in my opinion, I suggest that you begin with 1) Dohnanyi and the Cleveland Orchestra, and 2) the Schoenberg Quartet.
[There is a mistake on the site. Pierre Boulez is the conductor, not Helmuth Kolbe. Careful inspection of the box reveals that Kolbe was the engineer...]