Citronbull,
Make sure you have the current unit optimized before upgrading.
Have you experimented with different placement options and calibrated the entire system with a SPL meter yet? Every room is different, but corners tend to work well(for sub placement)---especially corners near the key seating locations. I would set all speakers to small in the receiver setup menu too. Also, please feel free to fax me a room layout. If you include the current speaker locations, the seating locations and any openings into the room---that would be great. My fax is (330)793-8183.
Tom V.
SVS