This two-part episode has a lot going for it: the excitement of having more firepower on the side of the humans (for once), and the excitement of meeting several new characters (most notably, Cain and Sheba). With this newfound power, the Battlestar Galactica is given a chance to stop and navel-gaze for a while: should they be running from the Cylons, or bringing the fight wherever they can? Cain's charisma and different ideology offers us one of the few moments to see a real ideological conflict between our hero commander and someone else with power.
Baltar's neuroses are brought into sharp light, often with hilarious effect: the surprise of a second Battlestar as he flies into the fray, and the hysterical outburst as he realizes that Cain is coming after *him* both offer us some laughs, as well as selling us on Cain's clever strategies.
This two-part episode is ultimately a classic of the series for its optimism, its strong characterization, and its ability to raise some hard-hitting questions about the future of the fleet while allowing for several scenes of exciting action and daring strategy.