I don't imagine you're regret it. I watched the finale earlier this evening, and I have no idea what I could say about it that wouldn't be a spoiler, so I'll just say Legion goes on my list of shows that "stuck the landing."
Just finished episode 5 myself, and a few minutes into six. Some thoughts on the implications of ep 5... I'm reasonably sure now that it was the collective and seemingly malign Legion personality alliance that took dubious sexual advantage / essentially rape of Sydney at the end of last season, not the main David personality fragment (who we're now starting to glimpse again) - or they were at least in his mental drivers seat at the time, directing his actions. That's not to make excuses for prime David or casually diminish the violation involved, just the impression that I'm getting retrospectively.
I've got to say the astral rap battle definitely won the "most Legion" Legion musical interlude prize, but the previous episode's whole-cast rendition of Nick Lowe's "(What’s So Funny ’Bout) Peace, Love & Understanding" was pretty amazing and moving also.