I never used the weapon since it looks ugly to me. I wish Assaultron's blade was a chainsword instead.
Its also a super lame weapon to use. Just hold it in front of you and *bzzzzzzzzzzzz*. I know. I'll do an awesome slow-mo vats kill *bzzzz....zzzz....zzzz...zzzz* zzz OH! Fell asleep there. Super lame.