Sorry, I don’t know what WWS means...
The way I read this is that you were not IN the demo room, but heard from a salesman about Yamahas “better separation”.
Ime, with different manufacturers, that sounds like a Dog Log to me.
Also
@Pogre, I would add to your comment about picking the AVR with the features you want. Try to get one that had a GUI that is navigable and menu structures that are intuitive. That’s my biggest bitch about Yamaha, is the menus SUUUUUck!!!!! And I hate their proprietary sound modes, and fukked up way to setup multiple subs. And ypao.....