Assaultrons are (IMHO) way OP particularly when you encounter them at lower player levels. I've yet to find a decent weapon or combination of weapons that can stop or slow them down sufficiently to prevent their devastating attack. Shooting arms doesn't seem to stop the weapons. Shooting legs doesn't slow them down. Complete nightmare and best policy is unless they are right near where you need to be, run away and find a different approach.
If one element of the game needs to be nerfed in the player's favour, it's these guys.
I disagree - it's nice that there's at least one enemy that takes a bit more thought/prep and can't be easily killed just by sneaking and 1-shotting, or running in and emptying a couple of mags into their face

Also:
You can see from my video above, pulse/electric damage takes them out pretty easily