Gene, I conformed your results over four years ago. In my amp controller I can also switch my power amps on and off. My amps draw far too much current to be turned on and off with the 12 volt trigger. So I have an amp controller I designed and built that works with 27 volt relays. The power amps are also connected to magnetic shunt breakers at the panel to absorb the turn on current. So I can turn the speaker amps on individually. There are 9 two channel amps in all, powering a 7.4.2 system with 3,200 audio watts.
My results are identical to yours, so I can confirm you results. We are in complete agreement. The only one that is any good is the Dolby Upmixer. I have the Marantz AVP 7705. The Auro 3D is awful and useless, The DTS is not really listenable. The Dolby DD Sur upmixer I find to be incredible.
I have a couple of videos you might want to view to see exactly how good it is.
The Scott Brothers Duo have incredible videos. I think Jonathan Scott is the best organist and transcriber for organ in the world right now. His brother James does the recording and filming. He is also a concert pianist and they often play duos.
Shady mentioned a recording of the Lichen Cathedral organs which are spaced around the Cathedral. Tom uses just one stereo pair of mics. On my rig the Dolby upmixer places all the organs correctly. Tom did put the larger organ which is at the back in front. So there is a 180 degree reversal, which was sensible.
The reason this works so well, is that with a single stereo pair the phase relationships are correctly preserved so the upmixer can work correctly.
Almost all recording engineers don't really know their craft. Almost all bung up and scatter around far too many microphones. When I was recording radio broadcasts on a regular bases, I used either a crossed figure of 8 pair, or the M-S technique. Since I often had non professional singers, I would gently spot them. Those recordings have preserved phase relationships and work very well with the Dolby Upmixer.
Here is another of Toms recordings. This organ has a division on the right. On my rig this division plays pretty much exclusively on the right surround at the side.
My experience is that the Dolby Upmixer does not work well when the recording venue is peppered with microphones, they are spaced and therefore separated in space and time, which is a technical disaster.
I am seeing on the concert streams I watch a very encouraging reduction in the microphone count of late.