I've been lukewarm on The Hobbit Trilogy. I don't think it needed to be broken out into three movies, there's a lot of awkward stuff that doesn't seem to fit the story because it wasn't in the original story, and the visuals just aren't up to par when compared to LotR. That being said, The Battle of Five Armies is the best film of the bunch and I think it's truest to the source material, with a few pretty important caveats.
I really dislike the Tauriel/Kili plot line because it seems completely gratuitous (much like the Aragorn/Eowyn/Arwen love triangle in LotR) - that's not to say that I don't like Tauriel at all: having an ass-kicking female elf in the series adds some balance, but having most of the discussions surrounding her be about whether or not she will be allowed to marry Legolas or if she is or is not in love with Kili cheapens her character. She's the captain of the guard, has risen to that position in spite of the odd caste system Thranduil has imposed, and she kills a metric fuck-ton of bad guys. And **SPOILER ALERTS** I hate that she's damseled at the end of the battle. She's been kicking ass and killing things left and right and then she can't take down a single orc and has to be saved by both Kili and Legolas, which ends up causing Kili's death. I mean, I knew that Kili dies in the book and that he wasn't going to make it out of the movie alive but I didn't realize that they'd have him make the hero's noble sacrifice to protect this frail lady-elf who got in over her pretty little head. Fuck that. I'd rather not have the character in the series than have her act as a prize to be won and the root source of Legolas's jealousy and dislike of dwarves. But for all of that it's still incredibly moving to watch her mourn Kili.
I'd also like to point out that neither dwarves nor orcs are stupid - having them stage a duel on ice is idiotic. These are supposed to be brilliant warriors, and having a fight on a frozen waterfall is not the sort of thing that brilliant warriors do when there's lots of nice, stable, grippy stone around for them to use as a battlefield.
Other than that the action in the film was pretty damned good and a lot less ridiculous than in either of the two previous films. There was no cartoonish chase through goblin tunnels or flippy-dippy-floaty battle/chase down a river. There was a fairly well-staged (though oddly paced) gigantic battle with five armies. We got what we were promised and that was nice.
Also nice was the proper development of the Thorin/Bilbo relationship - that felt very true to the novel to me and was heartwrenching at the end. I'm not going to lie, I cried when Bilbo tried to tell Thorin that the eagles were coming. Martin Freeman did a great job of getting the audience into that scene and making us feel the character's pain. **END SPOILER ALERTS**
Overall I liked the movie, and I'd be happy to watch the whole series again, but that doesn't mean it doesn't have some problems. It's a fun world to participate in in spite of its imperfections.