How expensive are PlayerState's for AI in multiplayer and why use them?

I'm using the ability system and have a replicated ability component and attribute set on my enemy Character class with things working fine but before I get too much further I want to be sure I'm doing things correctly.

Some examples I've seen use the PlayerState for AIController's and some don't so I'm curious on why to do it one way vs the other, for easier replication I'm assuming?

Also can't find much info regarding performance having several enemies with PlayerState's on them.