its amazing, but at higher levels, its tough to apply.
fox/falco - usually recover straight to the edge these days. often times, down angled ftilt becomes easier to use in these situations, like when they're above the ledge, and up b straight to it. if they're recovering above the edge, its often more applicable to bair them back off, cause with good di, the best an uair will do is sent them back to the edge.
falcon - usually just as effective to fair or bair him back off when he recovers high. falcon's rarely recover low on purpose vs ganon because they know they'll just get dair'd or tipman'd.
sheik - is just plain hard to edgeguard with any move. if you approach her, she'll just up b to the ledge and stuff. i need to work on edgeguarding her myself.
peach - uair is useful, if you find a way to get under her in range while she's recovering. bair usually does the trick as well at higher levels.
more or less smart opponents need to be hit with stronger stuff/things that take more space/cover more options.
at least thats my opinion...