1) The gigantic battle scene they've been building up to was every bit as freaking sweet as would be expected.
2) The ending was feeble. a) The writers truly did give up and decide not to bother trying to explain all the mysteries of the show, b) And so they made the characters all agree to give up as well.
a) The return-to-life of Starbuck; a Bob Dylan song being heard by the Five and guiding them to a new inhabitable planet; ancient written prophecies leading two peoples together; invisible beings visiting Baltar and Caprica-Six, etc., etc..."You've been waiting for an explanation all this time? Too bad, losers, because you aren't getting one. The answer is 'God did it.' So

you, viewers. We've been playing you for 4 seasons. How does it feel to be so stupid, dumb-assed so-called 'fans'? You could have spent all those viewing-hours learning to speak another language. You sicken me."
b) The characters: "I know - we've been working to salvage our civilisation from the brink of annihilation for years now and have had countless close calls. Now let's just dismantle everything we've worked for and live as tribal primitives. And everyone will agree with this insane course of action, even though it's perfectly obvious that they will change their minds the instant just one person they care about contracts a medical condition that can't be cured with tribal witch-doctoring, or when their young and mothers both start dying in child-birth at natural levels, or when this gorgeous sunshine passes and we can't keep ourselves warm in Winter/Monsoon-season/whatever. And because we've all given up, it's fine for Adama and Tyrol to go die alone as hermits on a hill somewhere. And Cavill, who fears death above all else, will commit suicide. And Anders will commit suicide too, as part of the process of abandoning all the technology they need to live as anything more than pathetic savages, and that their descendants need to escape thousands of years of warfare, slavery, average lifespans of 30 years, etc. etc. Pathetic.
Altogether, very disappointing indeed.