This is a bit of a cocktail but the performances are so good that if you don't have much of this music already, the set is an attractively priced compilation.
The five discs include a lot of Schoenberg in Wagnerian mode - two entire discs are devoted to Gurrelieder, and a big slice of another provides a delightful but slightly zany orchestration of Brahms' wonderful G minor piano quartet. So the set presents a fair bit of the "soft face" of the 2VS.
If that half of the production is the sugar, the pill includes the monodrama Erwartung (done extremely well by Phyllis Bryn-Julson) and Schoenberg's late Survivor from Warsaw. More familiar to the slightly intrepid listener is the Berg Lulu Suite, which is now well on the way to becoming a classic. Rattle does this well enough, but to be honest he and the CBSO are no match for e.g. Abbado and the Vienna Philharmonic with Juliane Banse in just amazing voice, which is available in various formats - particularly good value is an 8 disc box that covers more or less all Berg's music, which for me would be a much superior introduction to this period. But generally Rattle draws fine outcomes across the spectrum. He is particularly good in the Schoenberg Variations for Orchestra, luminously lucid.
A couple of irritants will bother the pedants - only three of Webern's five Orchestral Pieces op 10 show up, and the Berg Violin Concerto bizarrely appears only for its second movement. There is no text for any of the vocal music and the booklet's contents section mystifyingly ascribes the (post-holocaust) Survivor from Warsaw to 1909.
But don't let any of that put you off. This is excellent value for money and I have thoroughly enjoyed it.