I finally completed Legion. I would rank it among the best TV series in history, with the first season on Rushmore. The ending, as one of many possible ways to go, was more about closing doors than reaching a satisfying conclusion. I wasn't disappointed or blown away by it. I do like the overall arc of the series.
I hope people take it as a demonstration that you can do a successful show without sacrificing quality or dumbing down. There are parts of the show that are obviously well above my head, and I love swimming in those deep waters. I'm sure I'll be returning to this show, like West World, Mr. Robot, Black Mirror, American Gods, and Galactica, many times to further appreciate it. Art is important, and art made to reach millions of people is a miracle.