SL is pretty legit when used correctly.
Too bad even good MKs have a hella habit for using this move as a "panic button", imo if they used it more like Marth's oos where they ONLY used it for a read (like doing a quick SH SL to a whiffed aerial) or only used it when the opponent touched their shield with a misspaced move, then this move would be pretty hard.
Also I don't know about you guys and your opinion of Ganon, but this set is HILARIOUS, especially the second match:
http://www.youtube.com/watch?v=laRwODwOaZ0 also @ LzR: I would say that by the way you mentioned MK to use SL, Marth's would become "unpunishable" when used properly oos too, not to mention Marth's has more horizontal range and killpower (not by a lot, but you see some solid kill potential between 120-130%). Does that mean that MK's is only marginally better because it has a little more leeway if you whiff?[url=http://www.youtube.com/watch?v=laRwODwOaZ0][/url]