Past Prologue (OB 10 Jan. 1993) score: 7

Tahna Los: looks are deceiving

This episode has an early-days clunkiness, e.g., the characters are unsure how to pronounce "Bajor(an)."  Also, Tahno Los isn't quite convincing, but I have trouble taking a blond (man) seriously.  That foible aside, a solid episode, and early showcase for the series' secret weapon, "simple tailor" Garak.
 
DS9  wastes no time locating one of its major themes, the shifting line between national allegiance and progressive diplomacy.  Star Trek always made time for terrorists, although the spitefulness of this one's mission (blowing up the wormhole), and the story's emphasis on action over theme, soothed studio nerves as their new show launched.

As such, "Past Prologue" is a window to both of the political issues bound to sunder the franchise.  In the 21st century, even mixed sympathies for terrorism got pushed to the margins, while the franchise's resistance to gay rights became disastrous.

Admittedly I realized this long after the fact, but Season 1 teases Kira as a possible lesbian: there's no hint of flirtation with Tahna, and she's gradually less butch as the series unfolds.  Presumably, this was a half-hearted gauging of fan reaction, and again for Voyager (Torres, maybe Kes) and Enterprise (Malcolm).

When an organization becomes an institution, change is agonizingly slow.  Still, this long delay before inclusion is the franchise's greatest cowardice.