[smulloni]

I've never been persuaded by Rosen's account of that repeat. Most accomplished pianists are plenty bright and have read their Rosen, but don't necessarily agree with everything he has to say. (His preference for the early Schumann editions, for instance.)

[Aidevah]

Rosen did mention that persistent error eventually harden into tradition, and we get used to anything, and what we are used to becomes what feels right. On the other hand I have never heard that Chopin sonata before I read Rosen's arguments, so starting the repeat from the beginning feels right for me.

In any case the evidence seems incontrovertible to me. The majority of the earliest sources support the reading, Brahms felt it was correct. The end of the exposition prepares for the Grave perfectly both in terms of rhythm and harmony, and the Grave appears in the development so it's clearly not a separate introduction. Are there any evidence for the other reading other than "we've always done it like this"?