This release is unfortunately inconsistent with the magisterial series of Bartók piano works performed by Zoltán Kocsis for Philips, as it contains music pilfered from several volumes. Thus, since anyone in anything close to their right mind would want the whole series this release seems rather superfluous. That said, there is no way I can rate it lower than the top.
The main items are picked from the 4th volume, namely the Sonata and the Out of Doors - both of which belongs among the most important masterpieces of the 20th century (both were written in 1926). Kocsis meticulous attention to detail and his penetrating views of these works, combined with his spell-binding evocations of color where appropriate (Out of Doors in particular) and superb rhythmic command make for an incomparable listening experience. There is nothing exaggerated here, yet the music makes an impact that no other recordings are even close to achieving.
The remainder of the program is no less satisfying. The music is powerful, needle-sharp, mercurial and exquisite at turns, perfectly realized in Kocsis's performances. The sound quality is superb as well. Unmissable - apart from the fact that you would want the whole series rather than this stand-alone release of excerpts.