Hi Jfabes,
And welcome. I do many of the double-blind listening tests at Axiom and did do blind comparisons of the on-walls vs the in-wall/on-wall hybrids vs the in-walls. As Sir Quack noted, the in-wall hybrids on their own with no sub do sound a bit "fuller" with better bass than the on-walls and it's because of the larger enclosure.
By the way, you can get the QS8s in a paintable finish, so you can match them exactly to the interior decor. When that's done, you won't even notice them higher up on the wall.
Regards,
Alan
