Just got back from the 3D HFR version. I was not planning to go to this version because a review I read this morning said the HFR made it look very ametuerish, but literally in the parking lot on the way in an older couple asked if we were going to see the Hobbit, we said yes, and they said they saw the HFR version and it was very good and that they were giving out free Hobbit T-shirts after the showing. So we made the decision right on the spot to give it a whirl. The 3D was very good. NO motion sickness whatsoever and the previews of 3 other movies were in 3D as well.
There was a Dolby person at the movie who announced ahead that we were in 1 of 100 theaters in the U.S. using the new Dolby-Atmos surround system which is adding ceiling mounted speakers in arcs from front to back to fully envelope you in the scenes. We were in the upper VIP seating and on the very edge of the arcs so not immersed in the middle seating (they were already taken anyways).
I'm not much of a LOR fan but with dwarfs, hobbits, orgs, trolls, goblins, and few humans, it was a fast 170 minutes with just a few scenes that bored me. It was funny as well as full of action and more action. And the picture was really fine. UNfortantely the largest Tshirt they had was Xlarge so my son will have 2.