It's about the music for me.
But..... with better gear, it's like the difference of watching a VHS movie on an old TV vs BluRay DVD on a really good flat screen TV.
You're still watching the same thing, you get all the dialog, the same message and meaning, but the way you get it does make a difference. I wouldn't even hazard a guess at how to quantify this phenomenon.
Just what parts of the brain are benefitting from the added fidelity, are up for debate.
It's about the chair...the system playing the music just happens to be in the same room... 
The chair helps, no doubt.
Don't underestimate your surrounding environment either. I get the most enjoyment listening in the dark. I totally lose track of time.
Cheers
