Re: M-n in diff mode: use to a better spot?

[Richard Stallman]

    That would be fine.  Another possibility is for M-n to move to the
    first +/-/! line inside the hunk instead of to the start of the
    hunk.

That would look strange, I think.  Especially if it moves to the
"first" + line, in the second part of the hunk, because that comes
earlier in the source than the first - line in the first part of the
hunk.

So I suggest changing C-x 4 a's defaulting.