The bard in our game has gotten more good use out of Actor than literally any other feat anyone has chosen in our game. For example, he has done more with that feat in our game than my fighter did with polearm master and sentinel combined (which as I am sure you know, can be highly effective). Literally, no joke, the advantage on those checks and mimicry have been devastatingly impactful (particularly the mimicry).Well, that kind of glosses over the fact that some designer decided that in order to gain the actor benefits, you need to give up the Greatweapon Fighter feat (or somesuch).
In other words, you can think Actor to be a trap without devaluing its benefits or be a mere minmaxer.
You're paying a very steep price for Actor. I believe that to be a trap for everyone.
It is deeply campaign dependant, and also luck dependent. If you can't imagine it being one of the most powerful options in a particular kind of game, feel free to ask specifics.