Frank, if the QS4s are separated about 12', that should be enough. It's usually suggested to have them 2-3' above ear level, but 5' should still be okay(if that's what you meant), although if you want to change anything you might lower them a bit. So, it doesn't seem that there's much wrong with the positioning, and hopefully you've calibrated their levels. You haven't said specifically what you think is missing(keep in mind that the surrounds aren't supposed to be constantly loud and drawing attention to themselves), so it's hard to make suggestions.
