I remember trying Beyond Compare several years ago (after it was clear CompareIt! was abandon-ware) - it came close, but back then (for me at least) CompareIt! was a better experience. (It was also what I was already used to, to be fair.)

But I should probably take a look again and see how it compares now, because I can only imagine what vulnerabilities might lurk in CompareIt!'s stale PDF/Word/etc. viewers.

Almost any code movement/indentation changes seem to yield messy diffs in vimdiff, while CompareIt! (and others like Beyond Compare) could deal with huge movement and let you see what actually changed.