Excellent.
Actually, I play a few sonatas myself (some people say good, I rate myself low) and I am very familiar with them. Also many hearing with other pianists. I heard in Badura Skoda's a couple of notes different from my score and what I learn. Maybe his source is different. This does not reduce his quality.
I have the Beethoven sonatas by many other pianists. This version scores very high. I do not think I will be tired after frequent listenings.
He has also a set of Mozart Sonatas played in modern piano that are also excellent (Eurodisc).
In addition, I recommend his Beethoven and Mozart sonatas played on old instruments. These are also excellent.