" ... the story for "Unification" is jam-packed with exactly the kind of dry, political, diplomatic talk that sets Trekkies' hearts aflutter."
Hey, I like action, too. But, they aren't wrong. I do like "Unification's" premise and execution.
I think attempting the reunification of Vulcan and Romulus is pretty epic. Because the two are major players in Star Trek. A diplomacy mission between two planets/species of the week wouldn't hold as much drama to me. No way to know what might have been without something beyond "less talky, more action" about the idea. Learning about the thoughts and concerns at the time is interesting.
I enjoyed the surprise of seeing Dr. McCoy with Data, and I wanted more along those lines at the start of TNG. I was still craving more of the TOS cast, in addition to the films, at TNG's start. By TNG's third season I thought the show stood firmly on its own.