There's no point in trying to describe it, but when someone expresses interest, I sit them in the ideal location and tell them to close their eyes. After they listen for a few seconds to music that they are familiar with they are usually quite astonished and say something like "Wow!" or "I can see why you're so into this."
If you're not getting those kinds of reactions, perhaps your system isn't quite as good as you think it is. I find that when I listen to a lot of peoples' systems, regardless of what they have or invested; there isn't much happening because the speakers are so haphazardly set up. They're position has more to do where they look good or fit best into the room rather than where they will sound best. And another thing that severely limits the potential of a lot of systems is having the speakers so close together that there is practically no sound stage.