The series hasn't exactly been a thrill ride with all of its dark and profane themes, not to mention all the gaps and black holes in the "plot." Maybe this would make more sense if I had read all the tie-ins---but I doubt it.
To its credit though, the final issue was better than I expected. My worst fears about the fate of the DC Universe did not happen. The Multiverse was not wiped out and the ending was more-or-less "happy."
Of particular interest were the few glimpses into the new multiverse. We saw the Metal Men from Earth-44, a new earth on me. And who are these guys--a robotic Justice League? We see Overman of Earth-10, the Super-powered (former?) Nazi. And even Captain Carrot and his Zoo Crew make an appearance, rescued from exile on Earth-35. Aren't they actually from Earth-26? We also learned that Earth-31 (home of Frank Miller's "Dark Knight") and Earth-43 (home of the Vampire Batman) are unmonitored.
For that matter, are the Monitors doing anything at all now or have they vanished? I'm not sure. And what of Nix Uotan? What a surprise ending for him.
The climax of this story was the gathering of the Supermen of the multiverse. What a gathering! And they can only be assembled once. Maybe someone can find a way around that eventually. I actually counted over 52 variations of the original Superman on the two-page spread on which they all appeared. Does this mean some earths have more than one "Superman," or is there a reality outside the 52 universes, or did the artist just forget to count?
I also wonder how much thought went into the drawing of these Supermen. Do each of them have their own name, earth, and back story or was the artist simply given free reign to draw multiple variations of Superman? If each of these guys have an actual origin and location it would be interesting to see more of them in stories that develop their respective characters.
My biggest disappointment is that about two years after the return of the multiverse, it hasn't been developed or explored too much. We haven't seen many adventures taking place on these parallel earths or featuring their characters. I hope that changes soon.
The final two pages were the most intriguing part of Final Crisis. Who is the cave painter and could this mean what I think it means? Is he leaving a message for future generations to perhaps rescue a traveler trapped in time? Hmmm. I'm curious. Maybe Final Crisis wasn't a total loss, but IMO it could have been handled as a one-shot.