I just came back from seeing the movie, and here's my opinion:
Yes, it's not quite as good as the Lord of the Rings trilogy and probably a bit too long, but I still thought it was awesome! Technically and visually, the movie is a marvel, and the many quieter character moments worked really well, too. The returning actors do great work and I enjoyed Martin Freeman's Bilbo a lot. And Gollum, who looks even better than he did in the previous movies, is a particular highlight, of course.
If I have one major criticism, it's that during all of the spectacular, rollercoaster-like action sequences, there is never any sense of peril or stakes. Despite the fact that the big setpieces look like there's no way anyone could survive them, none of the countless dwarves are ever harmed or killed, which makes the whole thing feel awfully "safe" after a while.
And by the way: count me as a big fan of 48 fps (or HFR). The clarity and the amount of detail is amazing and the lack of motion blur really helps with the 3D and allows for very fast-paced editing and hyperactive camerawork without ever looking messy or jumbled. I think it's totally worth seeing it that way, despite some minor problems (a very "digital" look during the more brightly-lit scenes in the beginning, some movements that seem weirdly sped-up).