This was a fantastic episode, if for no other reason than because it brought back a somewhat lost element of the show: the friendship between Chuck and Morgan.
Of late, the weakest point of this fantastic show is the bifurcation that's left between the two: Morgan is relegated to comic relief side-shows with Chuck's Nerd Herd gang, the only interaction with Chuck being a few words in passing as he goes off on that week's spy mission. This cuts out a huge part of Chuck's life and makes the very idea of him being the Head Herder seem highly implausible.
Here we get to see the odd but surprisingly functional relationship between the two childhood friends and explore it, and that's a good thing.
The spy plot took a bit of a back seat in this one, which was more than fine with me, and it ends on a note which continues to pull our heartstrings on the undeniable love between Sarah in perfect fashion.