I really enjoyed this episode. To start with, I thought the team dynamic was excellent and it was good to see everyone working together to solve the case as a cohesive unit to track down the unsub and solve the case. J.J. seemed much more cheerful than she has in previous episodes and it was terrific to see Reid doing his "Reid thing" when Rossi wasn't turning the pages of his book!
Knowing who the unsub was all the way through actually felt 'right' this time because we could see how he was devolving and, more importantly, WHY he was behaving the way he was and why it was so necessary to him to talk to his victims after he had revived them. The two different perspectives from Reid and Emily about life after death were interesting as well. Two sides to the coin which has divided religious groups and the non-religious for a very long time.
Then of course there was the highlight of Hotch actually attending a case without wearing a tie. Most unusual.
I knew that Rossi's wife would end up taking her own life because he certainly had no intention of helping her do it. It was very sad to see their son's grave right next to hers, but fitting, I think.
All in all, an excellent piece of work from all involved with the show.