I've seen THE HOBBIT 3, and I have to warn you something.

First off all, I will only include general spoilers. By that I mean that I won't say anything you haven't figured out after watching the trailer and/or the previous 5 movies (this is a prequel after all, so you know which characters won't die).

The journey in L.O.T.R. was to basically save the world. The journey in THE HOBBIT isn't. Our heroes win the war of the title but it doesn't affect the Middle Earth that much. At least in comparison to SAURON's death. It ends with BILBO going back home and then it ties in with the beginning of FELLOWSHIP. Not exactly something that will you make you cry.

Therefore, when you go see this movie, don't expect the emotional impact and depth from RETURN OF THE KING. If you do, you'll feel empty. If you don't, you'll feel like you've seen a not-life-changing but fun adventure.

Also, remember that FRODO & BILBO were given different tasks. Neither of them fights in battles for the most part, but FRODO exhausted all of his energy ir order to do the thing that actually defeated the villain. BILBO was never meant to do any of that. If you don't keep this in mind, you might be frustrated due to BILBO's lack of duties and/or screen time (the lack is almost as big as in DESOLATION).