Simply put, the finale for this series was terrible. After some of the best writing I have ever seen on television for the first three seasons, the show began to fall apart in its final stretch and by this episode it was bursting at the seams. Rife with irrational character actions, pointless endeavors, and nonsensical plot endings, this series finale kicked off with Daybreak part 2, which is what I will detail in this review (my review for the second half will be listed under part 3). This episode was mostly where the action occurred, but it was poorly executed: the reasons for risking thousands to retrieve Hera is never actually explained (nor did it lead to anything significant), and the actual "break in and get her out" action was entirely lacking of tension or suspense. They basically dropped in, got shot at/shot people, and walked into Hera. The small scene with Boomer dying was a nice touch, as was the brief flashback. Unfortunately, it did little to make up for the lack of plot. No significant character deaths occurred to add believability to the danger these characters were in during this last, all out assault on the cylons. There were many, many places where characters or events were simply nonsensical and you could tell the writers were just trying to tie up loose ends, however poorly. To detail them all would take forever, so here is just one prime example: Tyrol choking out Tory Foster over her killing Calli, who he himself implied he never really loved but settled for and cheated on him, effectively ruining peace between the cylons and humans despite the fact that everyone was apparently cool with Tigh killing Ellen and not to mention the past thousands of years of history they all had, and then afterward everyone is just like "oh hey it's cool man" despite the fact that he effectively ruined the peace at stake for both races over one person's death.
It was moments like these all over the finale that ultimately made it one of the worst episodes to date. Things managed to get even worse, however, during the second part of the finale, Daybreak 3, which is reviewed separately.