I mean look at episodes like Far Beyond the Stars and In the Pale Moonlight pretty darn good acting IMO!
I'd say those two episodes are of outstanding quality despite
Brooks' acting. He very rarely managed to convince me in situations where he had to convey intense emotions, (self-) doubt, etc. I thought Brooks was better in 'calmer' scenes, as in day-to-day-affairs on the station, interacting with his son, or, for example, as the ice-cold and imperturbable warrior leading the federation fleet to retake DS9.