I'm still waiting for a response from Nakamichi regarding my question about Atmos source material. With regards to the soundbar, it should reproduce DTS X height effects utilizing DTS Virtual X. Unlike the Yamaha YAS 207, the Soundbar does have a decoder to interpret the height information, and then reproduce it using Virtual X. This will be interesting to hear, as in this case you will have a good number of physical speakers around the room as a basis for the Virtual X effect.
I did find out that all of the drivers on the Ultra 9.2 Soundbar are new and upgraded over the 7.1 Pro, which is good news.
Regarding Atmos, it's not just that it requires either ceiling or ceiling reflecting speakers, but it also appears to require fairly specific placement horizontally. DTS X can work with many different combinations of speakers.
The reason I speculated about whether the output of Blu-ray players had an effect on how these various soundbars handle source material, is based on the long discussion on the Samsung 950 thread, as that sound bar decodes Atmos but not DTS. It emerged that a number of players could convert the Atmos encoded discs into a form that the 950 could handle. It may be that this is converted to 5.1, but as the Samsung does have an Atmos decoder, and does also virtualize height from 5.1 sources, I was wondering about something similar with the Nakamichi.
I think with a number of these devices you have to simply try them, and not argue a priori what effects a particular device can and cannot do. I go back to my old TV with its simple surround simulation mode. I'm sure there is no decoder present, but with some audio sources I can hear effects far to the right and left of the TV, and sometimes quite a bit to the sides. Sometimes the effect is so dramatic that I look to see if something is actually there.
Even with the lowly YAS 207, I'm willing to bet some discs sound more convincing than others. One of the reviews I read tested the movie Spectre and also Inferno, and these apparently produced pretty pleasing atmospheric effects that were consistent with the film.