I think dressing the wheel was the main reason for the
better finish.
Very often the long travel feed that feels comfortable at hand cranking on better quality grinders proves better than crazy fast or crazy slow. I usually try to target that speed with a power feed.
I believe incremental crossing with too big of increments can cause sporadic wheel slow down and cause messing up the surface finish.
*It is not uncommon that .020 to .050 straight across cross-feed increments will give the best finishes on a warmed-up surface grinder having a fresh dress, or lightly used after dress with the take being .0003 to, 005 and wet or dry with having a decent over travel at the ends of long travel so to avoid heat build-up.
Down grinding usually achieves the fastest stock removal, and incremental cross grinding usually produces the best surface finish. Often a combination of these two technics produces the best productivity.
*Here is a video about surface finish all new grinder hands should see ( 8:44, 21:10, and 26:30 ) to end are very interesting. *But don't skip ahead because the whole video (about a half-hour long) is good to the very end.