The most important thing that a prospective buyer should know about this set is that these are NOT reissues of the classic Melodiya recordings from the 1960's; they were recorded 30 odd years later in 1996. Pity that neither Warner nor Amazon tell you that. The performances are tired and more self indulgent than the earlier recordings. The Poem of Ecstasy lacks ecstasy and Prometheus lacks fire. Svetlanov was one of the great conductors of the 20th Century, especially in Russian music, but these particular recordings don't do him justice.
The advantages are that the sound is better. The recordings are still multi miked as usual, but the engineers haven't fiddled too much with the peak to mean ratio which gives climaxes the effect the composer surely intended. Also, Svetlanov finds a Karajan like power in the climaxes, quite lacking in the older set.
Die hard music lovers won't be put off, but if you're new to either Classical Music or to Scriabin, seek out the old '60s set for a more authentic Scriabin sound world. Better still, if you can tolerate the grotty mono sound, try Golovanov, who is virtually guaranteed to blow your socks off!