Coming back off a long winter hiatus, the writers might have been tempted to make an event out of this episode. In a relatively subtle way, they did; we finally see the television version of Kyle Reese. But this organically introduced into the story as a part of Sarah's serious medical situation, so it made sense within the more measured context of the season arc.
I truly enjoy the pacing of this show, because they're taking their time to tell a solid story, rather than focusing on repetitive action sequences that will never match the pyrotechnics of the films. But it does challenge the expectations of many, and it certainly won't help them bring in new audience on Friday nights. The character-centric nature of the series could be the very thing that leads to a premature cancellation (despite FOX's unusual patience with the show thus far).
Sarah's journey in this episode reveals both the depth of her strength and the extent of her mental instability. It's quite possible that Sarah has depended on hallucinations of Kyle Reese to get her through trying times in the past. I thought it was interesting that the end of the episode made it seem as though Derek is beginning to fulfill that role in the "real world" now. (There are some shippy aspects to that, but I doubt the writers will be going there.)
John continues to stand up for his relationship with Riley, but he's showing a distinct lack of confidence in that decision. Cameron and Derek both contribute to that, but his attitude doesn't really change until he hears that his mother is hurt. Only then does it really sink in that choosing Riley has more than vague potential consequences. I doubt it will lead to John abandoning Riley, but he could be more conflicted than in the past.
Speaking of Riley, her decision to use a suicide attempt as a means of playing on John's sympathies, knowing that he resented Cameron's reaction to Jordan Cowen's suicide, is hardly the product of a well mind. Riley has been unstable for a little while now, and Jesse is still not helping matters at all. The Riley situation promises to end very badly for everyone, especially once Jesse decides she's lost her patience with the girl.
Unexpectedly, this episode also establishes Catherine Weaver as a sort of anti-Sarah. John Henry has become a child-figure for Weaver, and Weaver appears to be acting in his best interests by any means necessary. Beyond that, her motivations remain stubbornly difficult to pin down. Her company's growing market share in Coltan would appear to fit the suspicion that she is helping to stockpile and prepare materials for SkyNet, but her desire to develop John Henry using Ellison doesn't quite fit that model.
This is another episode that defies easy categorization. This still feels like a show that would fare better during a DVD marathon session, when the long view of the writers can be fully appreciated.