I agree and like to add that despite being dangerously close to being fanwank this as well as all the other fourth season episodes avoided this via telling not merely new stories with old ingredients but also telling something new about the Vulcans, the Augments, the Orions, the Andorians and so on.
To use the Orions, they were great not merely in and of themselves but also in terms of establishing the notion of a dangerous border trinagle area. You can really see the first 'space is disease and danger' notes in ENT (note also Archer's vacuum transport) which eventually led to a fully established theme in the new movies.
On the tidbit site, I liked that we finally saw Dr. Lucas, Phlox's human counterpart on Denobula, (the actor played together with Billingsley and Tony Todd in "A Man From Earth"), that the 'human experimentation with genetics gone awry' theme was tied into Data, thus providing typical Trekish optimism and last but not least the family stuff you already mentioned: the Augments have a "father", there is fratricide and near-patricide, archetypical stuff we know from mythology and religion.
Lest we forget criticism, I think that the follow-up to this story, Affliction/Divergence is a bit better, and I consider the Vulcan and Coalition of Planets three-parters to be better as well ... but this is moaning about the champagne tasting a bit worse than the caviar. While I view the three-parters of the fourth season as a brilliant way to tell longer, slightly serialized stories, something in between TNGish two-parters and DS9ish serialization, I also think that one of the three episodes often drags or falls a bit flat. In this instance it is the second one on the station, in the Coalition of Planets arch it is the third one.