I agree that Shadowplay
is pretty average - not bad, not great. It does have some good character moments for Odo and a nice final shout-out to the Dominion before their proper introduction at the end of the season (showing that they're not just an economic and military power to reckon with, but a power that is completely willing to be brutal in their methods).
But, I love what they with Jake here, even if it ends up meaning that he plays such a small role later in the series. When Nog joins Starfleet, it's not a rehash of Wesley Crusher, since he's someone who is trying to improve himself, not a child prodigy. If Jake had joined the service, it would have easily gone down that same route, which really would have hurt the show. As a result, Jake is much more sympathetic than Wesley to the audience, he's just another guy making his way in the world.