Yeah, "Day of the Dove" is a home run all the way. I've been watching season 3 of "Star Trek" for the first time and so far that's the only episode that I've found great and as good as any solid episode in the previous two seasons.
Michael Ansara is one cool dude. His acting in "Blood Oath" years later contributed significantly to my considering that one of DS9's best episodes. Here's a fun bit of geek trivia...his line, "You will die of suffocation in the icy cold of space" is now a bit of a nice unintentional foreshadowing of his later unforgettably brilliant performance as Mr. Freeze in "Batman: The Animated Series".
Whether he's doing voice acting or live action, his voice is always badass.