^^I agree, Smokey, I thought the placings sometimes seemed random. With that said though, I do think they all have great rapport with each other, and I think we get a different dynamic with each pairing. (I love how Nick pokes fun at/with Hodges, and Morgan is tough but lovable like Sara...)
Since I'm re-watching all the seasons on dvd, I'm loving the character progressions of everyone. I feel we come to know a little more about each of them...but it's kind of sad that, although I am enjoying this season IMMENSELY, I just don't get that feeling with the "old" characters, especially Nick. I don't feel like I've learned anything new about him this season.
It feels like mostly one-liners. In the old seasons we'd get to see him really working the cases, wrestling with all the facts and details, and through that we'd learn something about his personality or a particular viewpoint he holds. I'm getting that from the others, but not Nick so far this season.
I know that there were reasons he wasn't as present at the start of this season, and I know there are more episodes to come. I just miss the depth of Nick Stokes...he's such a great character that you root for.