I've recently upgraded my sub and DVD player, next in line is surrounds. I have Polk RTA11t mains, CS400 center and am using the mains I got with my Kenwood HTB503 HT in a box kit as the surrounds. I've been thinking about popping for the Polk fx500i surrounds. I can get them for about $350 for the pair. My question is how important is it to mate the drivers of your surrounds with the mains & center? Do the surrounds make that big a difference? I'm hoping someone else has pondered this and will be able to say upgrading the surrounds make a huge difference! or - save the $350 and keep the Kenwoods, surrounds don't make that much difference.... Thanks!