Richter's Liszt Concertos can't be beat, but I bought this CD to hear his versions of Beethoven Sonatas Nos. 10, 19 and 20, which are difficult to find on disc. Richter's rendering of #10 is delicate, passionate, playful, and intimate. He always does wonders with Beethoven's variations--check out his disc-full on Regis--and has a lot of fun with the march-like variations in the Andante section. Richter has less chance to show off his amazing technical skill with 19 and 20, both early "practice pieces" dating from the mid 1790s, but is poignant and convincing in eliciting their emotional content and deep musicality. Whether or not these are "definitive" recordings, you'll never listen to these pieces in the same way after hearing Richter's take on them.
Should these have been paired with the Liszt Concertos? That could be asked in another way: After hearing both Liszt Concertos, are you ready to hear Liszt's long Sonata as well? That's a pretty intense 74 minutes. I enjoyed the switch to lighter and less directly emotional. But if you don't have any recording of Richter playing Liszt's Sonata, you're missing out on something.