I dont know where I heard the sibilance at first listen. I've been listening to the MS-2s everyday and I dont hear any sibilance at all at normal volumes, except for some classical albums with tipped up treble.
The only downside of the MS-2s is the soundstage. The woody 225 has more depth that the MS-2 doesnt have. But the MS-2 has a much more cohesive sound, ala RS-1, HP-1000. I think MS-2 + bigger cups would be awesome