You can't put the -res proc in shockwave, and you can't benefit from the -defense in slash either (if that matters). Also, outside of AV's/Pylons, post level shift you'll knockback even level 54 Bosses significantly, so not as much use there. Unless you want the KB.
It's nice to break spawns with and buy time to regenerate health if you need it, but often, the KB is simply too disruptive deal with.
I mean, at some point trading in a power for fireblast actually does more damage than SW if you take fire mastery right (against a ST)?
"Fascinating. I'm not bored at all, I swear." -Kikuchiyo
I've never actually used shockwave (yet) but I can't help but notice it has the second best DPA of any claws attack. Seeing as single target DPS chains are usually used against strong targets that can't be knocked back anyway, is there any reason to refrain from using SW in a single target chain?
(I already ran some numbers, and with 3 damage enhancers in every power, FU>F>SW>Strike does 174.18 dps, while FU>F>Slash does 184.84 dps, but the shockwave chain requires 86% less recharge)