Mock multi channel audio is not positional audio.
Positional audio is an end to end process that requires two very particular microphones that mimic the way sound moves around out inner and outer ears, there are two of them because we have to ears and that's how we hear. Sony were one of the first companies to create this hardware in the sixties.
The way people interoperate distance and position in audio is through volume as it hits both ears and by the way the audio changes as it passes through our head. Positional audio in it's oldest form was created using two microphones, one for each ear which is then processed to mimic how the sound would change inside our ears and as it passes through our heads.
Due to this your brain hears the direction and depth of the audio source.
With PlayStation VR the process is similar but obviously with the recording stage, the audio is produced natively and the processor also takes into account which way you are facing so the source will move as you turn your head.
Virtual sound is completely different process and gives a completely different result. It doesn't attempt to mimic the way our ears work at all, it attempts to fake multiple speakers
and even real 7.1 are not the best way to mimic what we hear in real life because sound in real life doesn't just originate in 7.1 directions.
Positional audio is a specifically technical process which have been used to sell audio systems that don't even come close to what positional audio actually is. You will see it many sound systems and games but it is factually incorrect to label it as such.
There are different algorithms used for positional audio and some, as you'd expect, are better than others. Below if the first recording that I found on YouTube which obviously means that you're not getting the full audio quality but it doesn't do a particularly bad job what positional audio can do.
The better your headset is, the better the experience should be and keep your eyes closed when you listen to it your ears are hearing something that your eyes aren't seeing and that can reduce the effect.
The Interrogation Chamber - Amazing Binaural 3D Sound Play