There wasn't to much to enjoy, apart from the old guy story and the ending.
I think this show is going downhill, and it's starting to be proven now in a very subtle way...
For starters, Callie is being really destroyed, then you have the least interesting cases. Now dialogues are nonsense and the topics are often repeated. Music is good, but not as good as previous seasons.
In this episode they introduced a poor character, Norman, who I hated inmediately. It wasn't an appealing character, and the character development in the next episode is a proof of that.
Also, I used to love Gizzie but now it's all kinda anoying.
About Cristina, I think this is one of the last episodes in which she is herself. She can't say how she feels, and she taking advantage of Mer was so like her, It was kinda funny.
I also have to say that this was the last episode that I hated Lexie; from the next episodes on, she's going to be stealing the show.
MerDer? Don't get me started.
The rest? There's no using in saying anything else.