In the Chopin sonatas it's difficult to think of which performance to choose as the greatest.
Aside from the Funeral March itself, Rubinstein's account of the Second Sonata is a bit too imperious; the Third is much more thrilling, with considerable technical risks being taken both in the first movement and the finale. His own feeling for quiet nuances in the Largo of this work is quite superb, and here too Pollini on DG achieves an innocence that's disarming.
Pollini's disc is the most perfect, both in terms of the pianist's technical accomplishment and the lucid piano sound, with nothing that offends the ear. The middle treble range in Rubinstein's piano sound has a hollow resonance.
Rubinstein tackles the F minor Fantasie in rather a heavy-handed manner, with more power than searching drama. If you want your Chopin sonatas balanced and formally cohesive, then Rubinstein is for you.