This one's served fairly well: "Review this diff - detect top 10 problem-causers, highlight 3 worst - I'm talking bugs with editing,saving etc. (not type errors

This one's served fairly well: "Review this diff - detect top 10 problem-causers, highlight 3 worst - I'm talking bugs with editing,saving etc. (not type errors or other minor aspects) [your diff]". The bit on "editing, saving" would vary based on goal of diff.