May I ask you the reason and about the quality difference between the C-41 and C-41RA process?
I heard the C-41 process takes longer than the C-41RA process.
The only difference between the two processes is that the RA (“rapid access”) version uses different bleach and fixer, both of which act faster than the regular, non-RA bleach and fixer. The developer and final rinse are the same. For the Kodak Flexicolor chemistry, the non-RA bleach and fixer both require 6:30 in a Jobo (at 38 degrees C), whereas the RA bleach requires just 1:00 and the RA fixer requires 2:00 at the same temperature. Many people use slightly longer bleach and fix times just to be on the safe side, as mshchem reports above, but my experience using chemicals only as one-shot solutions suggests it’s not necessary. On a per-unit-volume basis (with regard to working solutions), the RA versions are a little more expensive.
I use the Kodak Flexicolor chemistry and have actually compared the results produced by the non-RA and RA chemistry side-by-side using 4x5 sheets of Ektar and Portra 400 (i.e., exposing two sheets of Ektar and two sheets of Portra, and developing them in the two different processes). The results are completely indistinguishable. I prefer the faster process, so I’ve switched to the RA bleach and fixer.
Hope that helps.