If you're looking at this page, you must already know that for many people and for seven decades Schnabel's Beethoven Society recordings of the piano works have been the benchmark against which all others have subsequently been measured. These pioneering recordings have had many incarnations and currently here at Amazon.com alone one can find the complete set on Pearl, EMI and Classica d'Oro. Now Naxos is putting out their series, which will extend to nine volumes for the sonatas and two more for other piano works. Wizard recording producer Mark Obert-Thorn tracked down multiple sets of the rare 78 rpm discs in Britain, America and France and took the best he could find to make these new recordings. He got rid of things like pops and clicks while leaving in a soupçon of surface noise (even between movements - just like there would have been on the old 78s).
I particularly remember listening, in my childhood, to the recording (on this disc) of Sonata No. 12 in A flat, Op. 26, and marveling at the whirlwind left hand in the Scherzo. Later, when I heard people sniffing that Schnabel had no technique, I knew better.
I needn't comment about the performances. Volumes have already been written about them. I suspect you're more interested in the sound quality. I've heard pressings from the Pearl and EMI sets. These new Naxos versions are superior to them, although the Pearls are a close second. And then there's the price. Can't be beat. Only one caveat: you may wish to wait until the whole set is complete and buy them in a boxed set.