WOW!
I thought I would have a definite yes-or-no opinion after seeing it, but I don't.
Points about HFR
1. Best 3-D I've ever seen. I usually have eye strain watching 3-D. The second the HFR started, I felt my eyes relax.
2. The detail was amazingly rich. People say it looks like TV or game cinematics. I think it looked more like a stage play. Certain moments, like when Gandalf was meeting with Galadriel looked as if you could step onto the stage with them.
3. Because of point 2, I had a hard time immersing myself into the story. The music also fell flat for some reason. It was like if you played Howard Shore at certain "dramatic" points in your day. The music would feel tacked on instead of enhancing. I really want to see the movie at 24 fps now, just to see if that really is why.
Take away: Go see it in 24 fps for the movie. Go see 48 fps if you want to be amazed my the technical side.
As to the movie itself:
It was long. I think PJ has plans to charge us extra for an special abridged version.
PJ took a lot of liberties with the story. compressing some things, expanding others. I still don't know how I feel about that. It didn't bother me with LOTR, so I think I'll eventually be ok with this too.