I saw it in HFR 3D, and...I kinda loved it
Honestly, I went in expecting to hate it. I loathe interpolation on televisions (aka. "soap opera effect"), so I expected to hate the 48fps presentation just as much. But, to my surprise, even though I had a lot of caveats, I saw a number of scenes where I felt the HFR look was extremely pleasing.
It IS difficult to explain in words. To begin, when the movie first started, I honestly thought that something was wrong. Not just an "oh, that looks different and strange". I truly thought that there was something wrong with the projector, and that the file was being played incorrectly! The best way I can describe it is that it looked like when you play a movie at 1.5x speed. It didn't look sped up to the point of being on fast forward, but it definitely looked like it was being played faster than it should have been. Like I say, the closest experience is watching a movie at 1.5x on a disc player or computer.
But then we got to the Shire, and that's the scene where the HFR look put a great big smile on my face. Everything just looked very realistic - like watching a live play rather than a movie. I went into the movie with worries about this very effect. I had heard that it sometimes looked like a play, rather than a movie, and I was worried that it would take me out of the fantasy setting, and just remind me that I was watching something fake and made up. But, to my delight, the realism of the HFR look during the bright, colourful outdoor scenes in the Shire really just gave me the feeling that this was a real place. A place that I could go and visit in real life. And I personally found that to be more engaging and engrossing, vs. the regular movie look we're all used to, which sort of keeps us at a distance, and makes everything just a bit "otherworldly". In HFR, I believed I was seeing a real place in the Shire. When I watched the movie again in regular 24fps, it had the normal movie look, which gave me the feeling that the Shire was someplace else - a place that didn't really exist. Again, tough to put into words, but the HFR look was definitely more realistic.
Then I noticed that 1.5x look again when Bilbo (the older version) was on screen and quickly moving around. Everything about his movements looked sped up and very unnatural. But then Frodo walked into the scene and his movement (which was slower) looked phenomenally real - again, much like watching a play.
So one of the things I realized is that actors will have to adjust to the new HFR look, just as lighting, makeup and effects must all adjust as well. It's a bit like when television went from SD to HD. The old ways of doing makeup and lighting just didn't look right in HD. Changes had to be made. And similar sorts of changes will be necessary for HFR as well, IMO. This being the first major release in HFR, the adjustments have not yet been discovered and made, so some images look very strange. But I fully believe that things could be adjusted.
This contrast between things that looked sped up and unnatural and things that looked amazingly real and lifelike continued throughout the movie for me. I never fully grew accustomed to the HFR look. I was always rather aware of it. But there was a definite back and forth as to the way in which I was aware of the HFR. One scene, it was looking really fantastic and real - giving me that sense that these were real people in a real place that I could physically go and visit myself - and then the next scene, it was looking oddly sped up and entirely unnatural. It was a very strange back and forth.
And the CGI effects fell into that back and forth as well. Certain effects looked much more fake because of the HFR look, while other CGI creatures - like the Trolls - had a great new sense of realism that I really enjoyed!
So the term, "mixed bag" has never been more appropriate. Peter Jackson used a lot of sweeping camera movements to show off the smooth, judder-free pans. And they looked fantastic when it was a wide-angle shot outdoors. Being The Hobbit, there are no shortage of scenes with people taking long walks outside
Those looked great as the camera swooped by. But indoors and up close, those camera movements were distracting and looked sped up. I found that wide shots and close ups both looked better in HFR, but medium-distance shots seemed to be what suffered the most from that odd 1.5x speed look.
So, to me, HFR holds a lot of promise. When it looks good, it looks really good! I was surprised how much I liked it! I just really loved the sensation I had of seeing an actual, real live place and people. But when it looks bad, it looks very strange. So, like I say, I just think adjustments need to be made. It's a learning process, and this really is just the first major feature to use HFR for a wide public release - so growing pains are to be expected. But once it gets nailed down, I'd very much enjoy watching movies this way. Not ALL movies, mind you. But I see HFR as being just another option and choice for a director to utilize if he or she wishes to do so. It's not the right choice for everything, but it's far from all bad, either.