An impressive collection, no question about it. The box set includes the four original Umsonst & Draussen releases in re-mastered form, accompanied by a booklet containing articles and photos (most of which are available on the official release site). You can also download the albums individually from iTunes (the German store, at least).
Most of the music is in the kraut-funk style of mid-to-late 70's Embyro, which is no surprise since they were involved in setting up the festival in the first place. The first album contains perhaps the most krautrock-orientated pieces, but is unfortunately marred by the mastering being done from an LP release (the original tapes were missing). The sound improves considerably with the second album, and although the music is more focused on kraut-funk, it makes for a more consistent listen. The third and fourth releases are both double-albums, over 90 minutes each, and diversify the range of music somewhat. That's good in one way, but certainly makes them feel more like compilations that the second album.
Very few of the recordings are available elsewhere (Embryo's 'Wir sind alle politische Gefangene' was released on the re-master of Apo-Calypso as 'Prisioneri Politici'), and most of the bands are pretty obscure. That said, a large proportion of the bands involve musicians from better-know bands; some 67 minutes of the 4 1/2 hours of music feature Missus Beastly and various off-shoots, for example. Six tracks (from four bands) involve Marlon Klein of Dissidenten, who also is responsible for the re-mastering of the albums. And that's quite aside from the various Embryo-related projects. Obscure some of these formations may be, but there's no lack of musicianship.
On the (slightly) negative side, the CDs don't exactly follow the original releases—there's no way the third and fourth albums would fit onto single CDs. So all the albums (except the first) are split across at least two CDs, which breaks whatever continuity the originals had. It's better than leaving tracks off, and at least you can import the tracks into iTunes (or whatever) and make your own playlists. Also, the promotional artwork that you might see around is slightly misleading: in my edition at least, the cardboard sleeves containing the CDs are generic and do not show the original album art. That's slightly disappointing in an otherwise well-made box set.
All in all, this is a set which is greater than the sum of its parts, or at least than the individual songs it includes. Perhaps one more for the fans (of Embryo and later Missus Beastly in particular) than the casual listener, it's nevertheless a great overview of the alternative festival scene in Germany at the time.
Verdict: Very good, especially for anyone interested in mid-70's krautrock.
[Review also posted on rateyoumusic]