Why waste time on exercises when you can be working on repertory? Learn Scarlatti sonatas. They will give you all the benefits Czerny claims, and at the end you will have some superb additions to your repertory.
Well, Czerny doesn´t claim anything. You should already know that it works.The purpose of Czerny is to aquire the most natural fingerings of piano technique, so you later use that most efficient fingerings without thinking. That is not present in the pieces you practice. Czerny studies are all composed repeating in different combination of keys the same short passage so you can internalize the fingering in all positions. That is a time benefit you cannot get practicing a Beethoven (his teacher) sonata. Unless you take a passage and repeat it in different keys, wich is not really practicing the actual piece.
Topic: Studies 