I watched it and the "Looking Back" special that preceded it. So, here's the thing with me that most of you might not agree with: I like to stay in my comfort zone with Supernatural. That is, I usually stay within the first six seasons when I binge watch. I know there are great episodes after S6 (Baby, Fan Fiction, etc) but those first six are so well done that I rarely stray away. So going into last night's series finale all I had to reference it with were those first six seasons and, well, I could see the passion and drive just wasn't there anymore. It looked like a series finale that needed to happen and maybe was a little past overdue. It sorta reminded me of The Office series finale where the actors had long since fleshed out their characters and were just kinda mailing it in.
As far as the overall conclusion to their story, I liked it. I feel like we've all watched them suffer and sacrifice for sooo long that they finally got the ending they deserved. It wasn't over complicated or contrived...just a nice simple ending for the boys. I did have some issues with the execution of the episode though. Dean's death felt too easy considering everything he's been through for 15 years. They just gave up and let him go. Sam's story, on the other hand, was a little more unconvincing. Apparently, he gave up hunting and had a family and grew old. Which is where I run up against it. Sam in a painfully obvious fake grey wig was a little too much. They just didn't put a lot of effort in making that segment more believable.
That being said, it doesn't really matter anyway because it's all about how their story ends. I'm happy with they way they ended it but the truth is Supernatural will always be on for me as long as I have a way to watch.