I strongly recommend the recording of Feinberg's sonatas by Christophe Sirodeau and Nikolaos Salmanatos on BIS. Sirodeau is a good friend of mine but I heard a recording of his before we actually met so I may not be that biased. The sonatas 1-8, and nos.1, 2, 3, 4, 6 and 7 are very good in particular. The others were written when Feinberg had simplified his style somewhat (as many composers did in the 30s and 40s after more modernist beginnings such as Bartok and Szymanowski), but are still pretty good, the ninth being impressive. I've played nos. 1, 2, 6 and 7; I played the Sixth (possibly the best) in the last Raritaten der Klaviermusiks at Husum last August. Feinberg, although inheriting certain facets of Scriabin's style (he actually played to Scriabin as a very young man, and Scriabin thought Feinberg's interpretation of his 4th Sonata the best he had heard), is by an large a more interesting and original composer than Roslavets, in my opinion. Christophe has made a very interesting Feinberg page at something like skfe.com, also dedicated also to Skalkottas. Have a look!
Best wishes
Jonathan Powell