I'm planning to put my money down on either Mirage OM7 w/center or OM9 w/center.I already have a sub.Will power w/Marantz sr7000.I can't decide which speaker to get.Can you guys help me out.Is there a big difference in sound between OM7 and OM9.There is a $500.00 difference in price.I'll be getting them at 25% off.Help me if you can.