Samson Francois is more well-known in Europe (or even in Asia) than in US.
Philips, advised by Alfred Brendel among others, presented Samson Francois as one of the greatest pianists of the century. In Philips' list, we do have some extraordinary Chopinists. Fridedman's Mazurkas are said to be unsurpassble, so are Cortot's Preludes & Etudes (or all his Chopin), or Lipatti's Waltzes. Or else, Hofmann's or Rachmaninov's Chopin are just marvelous. But those are historic recordings. While some prefer Moravec or even Arrau's Nocturnes, Rubinstein's Nocturnes, and particularly his Polonaises, like Agerich's Preludes are a sensation. Cziffra's Chopin is superb, so is Freire in general. But we can't leave out Samson as a leading Chopin interpreter.
Samson was perhaps the greatest of Cortot's pupils. From his Chopin Ballades, there are all-embracing colours (by the subtlety of using the pedal among other things) creating rainbow after rainbow. The harmonic suspensions as the nub of the Ballades adds so much to the potency of music. His Nocturnes, darkening the colours in the background creating the right atmostphere together with the poignancy of his narrative power, compare favourably with Arrau's. His Preludes may not be a fiery as Agerich's, but they are more bitter, so bitter that he is a type of his own...
The Nocturnes are recorded in '66. And in any event the earliest recording in the boxset was made in '54 and the re-mastering is so good that unless you make an effort, you won't be able to tell them from modern recordings and yet they are sold at bargain price. Grap it while it is still available.