I hate to say it, but I was underwhelmed. It was OK to me; no more, no less. The 48 FPS was a little jarring at first, and I didn't really care for it. The high frame rate caused the opening scenes to feel (again, IMO only) like a poorly-filmed cheap set piece for a soap opera. Not that good for close ups. For panoramic vistas, however, I TOTALLY get it.
The 3D bit was pretty well used. There were definitely scenes in this where the 3D was just beautiful. If someone was going to see this movie just once, I would certainly tell them to see it in 3D. Scenes such as the rock giants (more on that later; I have a beef) and the panoramas of Rivendell were VERY cool to see in 3D format.
I could describe in detail the reasons
why I didn't like the film, but I don't know if people here want to know exactly how much of a dork I really am.
In short: too many unnecessary additions, a few obvious and unfortunate scene cuts, and the ridiculous outfits of the dwarves. Oh well. I saw it. Won't be seeing it again. Not even sure I'll see the next two. I prefer my "Hobbit" memories untarnished. Heh.