OK, out of curiosity I played the youtube videos on my system from my Shield. The metronome one was VERY handy as it made it really easy to set my "dialog lift" levels on the mixer to be exactly the same height as the left/right stereo lifted channels (i.e. switch from Stereo mode to DSU to compare or more precisely use the "Center Spread ON/OFF" mode to change it instantly. Now I can tell exactly a ZERO difference between the center channel being used for music or not being used from the MLP. They sound identical (helps to have an identical center channel speaker). I had to adjust the center out level as well, of course (by raising the mix sent to the heights, that made the center overall too loud). This also made center dialog clearer for the second row center chair (which really needs raised up a bit with a platform to have an eye view of the center speaker). With more output from above, it sounds quite acceptable now even without raising it up and it's hard to tell from that distance the precise height of the dialog even if it's a bit higher.
Anyway, back to the modes. Yes, the metronome sounded a bit "weird" in Neural X. I would not say it sounded like the VOG speaker, however (someone have their upper speakers turned up too much?) It actually sounded like it was coming from almost everywhere with a bit more in front of me than around me, so kind of odd. DSU and Auro more or less sounded the same as stereo in its position.
The Careless Whisper song.... I think Auro sounded the best, but that might be because it's both louder and has more bass output at the same settings (kind of annoying really when you want them to "match" as best they can). I had to turn Auro's depth up to like 12-14 to really hear an enlarged room effect (medium/large had less effect, I think). It basically sounds like the room gets a bit bigger (subtle reflections and some reinforcement). Neural X comes out slightly higher in elevation in Neural X than DSU for me, but they weren't as different as I thought they would sound. Yes, putting my ear to the surround speaker you could hear slightly odd sounds (stripped reflections or something), but at the seating positions, it didn't actually sound that different to me.
Instead, I put on some material I'm really familiar with. I put on "Father's Son" by Tori Amos and compared. Again, Auro cranks the bass and levels so I had to adjust the volume down and try to ignore the extra bass and listen to placement of sounds instead. That song has overdub echoes of Tori's voice that in stereo repeat what she says into the room a bit and towards the sides (out of phase). In Auro, the room sounded a bit larger and more reverb. That was it. With DSU, the overdub repeats of some of the lyrics sounded often BEHIND me to the sides going well into the back of the room (one set was more towards the front and sides, but most were definitely behind me). Neural X also put them further back into the room than stereo, but not as cleanly/clearly, IMO and the overall soundstage was slightly higher. My preference was by FAR for DSU on that song. That effect gave the song a really neat surround effect that was plainly audible and clear.
I put on a more rock-like song by her on the same album (American Doll Posse) called "Code Red". This song felt kind of odd with DSU and/or Neural X surround effects, IMO. It starts putting instruments around me that probably didn't belong there unlike the previous song that just did vocals and percussion and what not in the surround channels. Auro did the room thing, but again the sub level had to be adjusted to keep it from being overpowering. I'd probably set the sub level on a memory preset for Auro or something if I was going to use it often for music as it's like 4-6dB higher or something than other modes. DSU was the least offensive of the bunch, but I think I preferred stereo on this one.
Billy Idol's Cyberpunk album has a lot of out of phase effects in places that can give almost 90 degree effects with just stereo (might be Q-sound or something similar) and so the surround modes had less effect with those sounds (they imaged more or less in the same location with or without), but some other parts were shoved back that weren't in stereo. I'm not sure if that was good or bad. It probably would depend on the song.
Overall, I'd say I'd have to try the modes to be sure which I preferred, but stereo is always a safe bet. I think Auro-3D works well for jazz/live stuff where you want to liven up the room and/or extend it back for more than one row of seats. For everything else, I'd either go DSU or stereo. Neural X wasn't as bad as I remembered, but it did tend to put piano and things very high in the air in the front like I was sitting below the stage or something. DSU kept it more or less at ear height (or just above near the center of the screen due to dialog lift, although phase effects sometimes puts them lower regardless for some sounds, which works out oddly well as it gives more separation for some sound effects, but keeps major sounds and dialog at screen height so the voices and sounds come out of the screen instead of below it.
I also tried a modified Multi-channel stereo mode (reduced overheads) and it worked well for the back rows to liven the room up (kind of like Auro on steroids), but overall wasn't as clean sounding to me as stereo for the front.
