Regarding the new tech, the 48 fps was noticeable at first in that it was a little distracting, but the eyes and brain soon were used to it and it simply looked and moved great. There weren't many moments when 3D stuck out. Jackson didn't us it for many gags, but rather to enhance the realism of the experience. Subtly done really. Worth the extra money to see the movie as he intended.
The story largely tracks the book, with some additional stuff from the LOTR appendices. For the non-fan, the movie will likely be a long slog of storytelling, however cool the fights scenes and well written the dialogue. For the fan, it may not be long enough. It satisfies the craving for a Tolkien fix and then some. Dividing one book, albeit with additional material from elsewhere in the Tolkien canon, into three parts was always going to feel artificial to a degree. But as a first of three it works well.
Non-fans should go to see the new tech and a good movie. Fans can't miss it.