Camera Raw 12.3: Previews greater than 1:1 are now better!
Previewing raw images in ACR 12.3 at 1:1 and higher seem remarkably smoother than in earlier versions. LR had this smooth look so seems that ACR more LR-like in this way. But this change not mentioned in any of the What's New promotional materials. Not sure of this is true, or just me imagination, bit I like it!