i use it on hybsin, where traplayspeed, like you say, matters a lot

= trap damage output
the only drawback of using wsm buged wf + runic (fastest claw combo + highest average damage fools claw possible btw) is that you got fools as offhand and you loose the first free hitcheck with fools, but get it with chaos (lower ar & dmg if dont have zbug) instead.
wf + runics is a way to go for best average damage + speed, but you loose the intital free hitcheck, just that
BUT
since there arent zbug runic chaos claw, unless u wanna use eth runic chaos with dura like KD does > bm, the zbug chaos suwayyah + fast fools claw is better ( specially an eth feral like mine

)
2x eth claw FTW, imo theres no discussion about it, is there?
@moxer
don't try things in heroeditor vs monsters, try them @ open bnet vs chars instead, believe me ^^
http://i51.tinypic.com/28m2aw.jpg
You can use wf+runic and get 9 fpa without wsm bugging, that's when that set-up is actually good (since like you said, it provides the strong possible initial hitcheck), if you have to wsm bug them I wouldn't bother using that set-up since the primary claw is way too weak.