Saint-Saens didn't believe that music must express deep emotion to be worthwhile. He was more interested in beautiful surfaces than in profundity. The composer's aesthetic, which might be described as "decorative," justifies certain limitations and is not all that different from Milhaud's or Poulenc's, although the musical idiom is more 19th century than 20th century.
Because this is a "complete works" set of CDs, the quality of the compositions is predictably uneven. Several of the many pieces included are too protracted, formulaic and even dull, but few are without any interest. Almost all seem impersonal and dispassionate. That said, much of the music is lovely, frequently colorful and occasionally dazzling. Saint-Saens' piano writing is almost always transparent, elegant, ironic and wry. Some pieces, like the Scherzo for Two Pianos (which is organized as a palindrome), the Valse Gaie and the Etude en Forme de Valse, are stunning mixtures of modern musical language and traditional gestures. There is truly no other music like this.
Admirers of French music are fortunate that Vox decided to reissue these performances, which range from adequate to excellent.