For me this was a strong episode, thought not quite on par with the first couple. Still, this is clearly the best Sci-Fi on the air right now and as such, I'm grateful when there's such a drought of quality Sci-Fi programming.
While Noble continues to impress me every week with his acting abilities (that goes far beyond the abilities of any actor from the 9 years I followed the X-Files, btw) it's really been Torv who's convinced me that it's just her "real" earth character that's so plain/subdued. She's really doing a great job selling the stories that her characters on both sides of the fence and both are very real, believable characters so kudos to her.
The amber storyline was pretty interesting and raises some meaty issues to deal with, though nothing to original as casualties of war are a pretty common theme. As Fringe does often though, it takes this theme and spins it on it's side so that the "causalties" aren't dead, but stuck in a perpetual stasis where they are somewhat cognizant of what's going on around them. Of course, that's horrific but the alternative is the destruction of their world so it's pretty clear the stakes are pretty high on that side so it's not too difficult to empathize with their plight.....something not all that easy to get an audience to do I might add.
In any case, I'm ready for Olivia to get back and confront fauxlivia any time now and start building towards the ultimate confrontation between the two universes that I'm sure will probably serve as the climax.
Big question is where do the observers fit in? Probably not from either reality so where's their place?