"fast attack" has a 2 second charge up, and ghosts thru the target, doing no damage. power attack is a CRIPPLING 4 seconds of standing still. Literally only good for incapacitated unguarded tanks and quad guns.
Power attack is working as intended. Fast attack animation is working as intended. The only thing broken is the damage on Fast attack not happening.
also you clang with a knife even if its a power attack. Even if they are also power attacking you. It also does not break d-bash. Basically if someone is fighting back in any way except shooting you it is stopped. And since they can shoot you to death in 4 seconds and it has a teeny tiny bunny hop for distance, the most iconic ork weapon is worthless.