I don't seem to be able to watch episodes on ABC.com here, unfortunately.
Yes, I liked season 5, but I thought Castle himself was getting a little too silly, insisting on believing in ghosts, bigfoot and what not. And there were a few times when I thought "Wait a minute, I've seen this before". Drone hit on car (was that NCIS or The Mentalist or what?), red tap water from dead body in water tank (CSI NY?).
Still, a very enjoyable show. Can't wait for S6. But I guess I'll have to...