There is not that much to add to the other reviewer's comments: these two discs are a bargain and unreservedly recommended. Ashkenazy is indeed the very best overall Chopin interpreter around. I immensely enjoyed his treatment of pieces such as the second scherzo and the g minor ballade. Not to mention the etudes, the preludes, etc. etc. Ashkenazy is never doing stupid things, such as beating the hell out of the numerous fortissimo chords. Instead he offers a very pleasant sounding forte at a ferocious Steinway. All is crisp and clear, and the fact that some recordings are analogue doesn't matter at all: in fact, they are hard to be discovered.
But keep something in mind: as I said, Ashkenazy is arguably overall the best. This implies that he can be bettered in some ways. Philips has also released a Best-of Chopin set, which contains better renditions of some Waltzes (Kocsis), the Barcarolle and Mazurkas (Kovacevich) and the impromptus (Davidovich). Additionally, the Philips discs give you the Marcia funebre, the Fantaisie-Polonaise and the fourth Ballade, three big pieces that cannot be found over here. Overall it is more balanced too. So if you are going to buy just one best-of-Chopin set, go for the Philips. The best choice, however, is to get both of them!