If you listen to this recording repeatedly, and then compare it with other good or very good recordings (Lipatti, Serkin, Moravec, Staier), you'll notice the differences: you will be aware how these latter pianists search for the correct interpretation of certain passages, and often they succeed. You'll be also aware, however, that Richter does not interpret. He simply plays it the way Schumann must have intended the work, i.e. the way it has to be played. It's not a matter of technique - in this respect, many(but not too many) pianists are as good as Richter. It's just like Schumann's spirit has penetrated Richter's nervous system and guides his fingers.
When you're not listening to the concerto for a long time, and then try to "play" it in your head, you will reckognize that it "sounds" like the Richter-Rowicki recording. And you will notice flaws in all other recordings.
Summarized: Best recording of Richter, best recording of Schumann's piano concerto, and my all-time favorite recording.