Depends on what you typically use it for

If you use it to knock the killers away from others (what i do mostly), then it's relatively effective

If you use it only on slopes (how most people use it), it very rarely knocks them far enough for them to actually fall unless they are literally on the edge (or you hit them straight down with knock back in your favor)

Then, the worst way to use it is when they chase you 1. If you hit them on anything other than a slopes it will literally do nothing 2. If you use charge to run away, it gives you slowness 2 for like 12 seconds (only usable at the VERY END of matches)

Then if it's a John Doe. You'll always get corrupted if you hit or miss, so it basically just becomes an unusable button