I think this episode was solid, I'd probably give it an A- or so. I think all of the various elements of it worked, the humor, drama, the premise the allegory it was going for and so forth. Nicely done. I have questions though about some aspects of it, but I'll address them later. To compare it to "Who Watches the Watchers?" I think this one came across a bit better in showing the ramifications of societal contamination, deities, and the evolution of a religion over several millennium. It's interesting though that, apparently, their further cultural contamination didn't further damage/jeopardize their careers. But, I guess we really don't know how their "Prime Directive" works but it seems there is something of one when it comes to highly primitive cultures.
I don't see this going out on a low, I see it going out on something of a high, if not just level. It held my interest and made me reflect and think. (For a moment when the planet reemerged for the final time I had thought that maybe Issac had done something Bog-like to them given his indifference or regarding of humanity. I guess this shows how "good" he is and his general intentions and the like that he was able to stay aside and silent for 700 years and not take over the planet or something of the sort.
Again. Good and solid.