The crimes and victimology in this one were horrifying, especially since there were no survivors among the main targets - sure, the kids got away at the end, but all seven fathers were taken away from their families. Not the kind of case I'd consider to have had a happy ending.
But paradoxically the unsub was the sort who's so far gone you can't even hate him - well, for driving drunk with his son in the car in the first place maybe, but the killings rung of brokeness rather than evil. (...although, yes, it was very reminiscent of Evil).
Hated Prentiss's relationship getting shoehorned into the confrontation with him, however. Maybe it's just me, but I wasn't getting a 'star-crossed lovers' vibe from her for most of the episode, more like an 'ugh, you again' one. Guess it worked out for them in the end, but I always get the secondhand cringes when one character keeps chasing after another who's blatantly trying to rebuff them.
If they wanted a personal connection to the unsub, JJ's miscarriage would have made her a better fit.