I watched it this morning. It was pretty good. I agree that it didn't quite have the emotional punch it seemed like they were going for, with all the "family" and "what we're doing all this for" both literally and figuratively, but it did what it needed to do. Nice special effects. You could tell they saved up some of the budget for these two hours. We started the season was some nice location scenes in different time periods, then we spent a few episodes inside the Lighthouse and holed up in the Zephyr a lot. But we got the big fancy ending. Fitz is back, Jemma's memory is back, they have a daughter, Zeke's existence is (insured? possible now?) and everybody's different, but everybody's the same.
I save a lot of episodes and watch them a second time, to catch all the stuff that got past me the first time, but I've found that it doesn't help me as much as the various discussion boards actually talking about the episodes. People point out things and/or explain things that I didn't get, and vice versa.
One thing everyone seems to agree on is that Nathaniel, Kora, and Sibyl were all boring as fuck, and that brought down this season overall. Garrett wasn't much better. I've gotten to really like most of the main characters, but this show always had trouble getting consistently good bad guys, and this season was no different. And that's sad because you want the wrap-up of the entire series to be something really amazing, and it was just "pretty good". But hey, nowadays I'll take "pretty good".
Overall, the series challenged me a few times, surprised me a few times, and generally kept my interest. My wife and kids all bailed on it years ago, but I stuck with it, and I'm glad I did. I don't actually watch a lot of TV, so once I get into a show, I kinda want to stick with it, having already invested some time in it. I don't want to bail on a show and then find out later that it got really good after I'd stopped watching. That happened with Deep Space Nine, which I still want to watch again, but if I do that, I'd want to start from the beginning again, and it's that first season that really kinda bored me and made me bail in the first place. Life's a bitch, eh?