I hate when a series has such a disappointing ending that you feel angry you've wasted time investing in the show. I don't feel that was the case here.
No, everyone doesn't "live happily ever after," but then it's post-apocalyptic, dystopian sci-fi, so what do you expect? I'd be disappointed if they did.
Good character arcs, & redemption for those that deserved it.
My one big frustration was that throughout the last several episodes, but ESPECIALLY this one, they know they have very limited time on the surface, yet you almost NEVER see anyone hurrying, much less RUNNING. The fate of two worlds, BILLIONS of people is at stake and they can't muster up a slow trot even?!!? WTH??? There's just no sense of urgency at any point, knowing connections could be irrevocably broken at any second, and it's still "Hey! How's it going? Bob sends his love" type small talk. Ugh.
Other annoyance was the fact that in England, where weapons and ammo aren't as easily accessible as the US, they seem to have endless bullets to shoot at all metal robots, when it seems like some good spears, lassos, bolas or the like would have been much more effective (not to mention quieter). I hope the UK isn't developing a gun fetish too.
Otherwise, has next to nothing to do with the H. G. Wells version, but still enjoyable.
NOTE FOR THOSE NEEDING SUBTITLES The diverse cast was nice, but side note- they really need to coordinate subtitles with in show text. It often said "Speaking French" over the French translation in show, making it impossible to read. My French is good enough that I usually got by, but a few times had to turn off subtitles, rewind and watch for translation, then turn on again. Really annoying.