Both. Set the ocular for the reticle, the side parallax for the image. You might need to monkey a bit with both to find the sweet spot for your eyes.
For my eyes, the 4200's are way better. however, the 6x24-50 does loose a bit of resolution at 24X vs the AO scopes.
I used quite a few 3200's but gave up as they just didn't have the resolution/clarity I needed.
Jerry