Mark, as Randy pointed out, the currently published specs on the 350v3 may not be totally up to date(for whatever reason). Both the changes in design which were made and reviews, including Alan's double-blind test results, indicate a significant improvement.
As to placement in a square room, simply putting two subs at convenient locations probably won't be significantly helpful with room modes. The literature published by Dr. Toole's colleagues at Harman, and others, indicates mid-points of opposite walls. For example, at mid-points of opposite side walls the subs are at a minimum point for the room length mode and the room width mode is opposite in phase at the two side walls and tends to cancel.
