BiS mainhand for Savage Blade COR, seem to be pretty popular offhand choice too. That being said, blurred knife +1 offhand offers more gear flexibility since OAT has more value in a low multihit dt- set or max acc set.
Although Sapara +1 could be a competitive choice in high multi attack tp set as soon as you swap to low multi attack tp set blurred +1 pulls (quite far) ahead.
tl;dr: Use it for mainhand, try not to use it offhand.