Played around with it in the sandbox and immediately disliked its insistence on putting every item in a sufficiently-long array on its own line. For example, something like:
Only if I add an item in the middle. If I'm always appending, then only the last line will show a diff, and said diff will be for the added entry.
Even in a case where I need to add an item in the middle, the diff will - again - only start where I actually added an item, and any human can readily see that the rest of the downstream diffs were from the reflow.
Of course, it'd be even better if diff tools were more aware of the format/language of the code being diff'd, at which point it'd be able to say "new element added to foo" instead of reporting on a bunch of reflowed lines.
The default line length of 88 also seems weird, but at least that's readily configurable to my preferred 80.