I just tried the links at the following URL
http://www.audiocheck.net/audiotests_ledr.php
The 228HT has great stereo imaging - sounds like the center speaker is on in Stereo. But I'd have to willingly swallow a placebo pill to believe I was hearing the things exactly as described in that link. I wagered you'd be just as likely to confirm the sounds were going down as up if you were told in the accompanying reading that they were supposed to be doing so. So I called my Wife down to do a little test. I had her sit in the sweet spot and I played all five tracks for her telling her they were tracks that would move speaker to speaker and that she should draw what the sound did.
The first one she drew left to right
the second right to left
3rd she drew an arch (interesting because that is correct)
4th she drew a straight line (also correct)
5th she drew below the speakers
I asked her to identify the last three separately again blind in random order. She missed 2 and got one right in the retest. Oddly enough the one she got right was the arched one.
So there is some sort of trickery going on with arch in my limited testing with my wife as the subject.
If you can do height - then you should be able to depth, but I don't see demos of that - even in binaural recordings. Binaural tracks with headphones are very cool, but even that doesn't really do height that I've heard. And that's very much not what the mention of spacial height recognition was talking about in that review --- they were talking about a regular recorded track having height imaging - - not a binaural recording specifically recorded with many mics and custom made to offer a surround sound like experience on your headhones. Regular/typical recorded music containing height information ---- shouldn't be happening.
I'm thinking of the requirement of triangulation being required to pick out an object (sound) in 3d space. Perhaps that's not appropriate - but that's what originally came to my mind and why I said three sources required for true 3d spacial recognition.
http://www.kowoma.de/en/gps/positioning.htm