You're still gonna need to allocate some mag boosts in accuracy in order to keep from missing too much, though. Especially with... anything not a shuriken. I'm running a Shuriken+Shinobi Suit on my HUnewearl (Who has the best accuracy a hunter can get), and I still had to plan around adding a bit of accuracy to my mag. And you lose a chunk of accuracy with non-shuriken slicers.

They're best as mind-based boss weapons. It helps that Reyburn's head can be hit multiple times with one attack after the horn is broken off, and the other bosses (save for Humilias) can easily have multiple targets hit with them.