Has anyone had any luck, or can anyone provide an opinion on, mixing Polk spreakers with Def Tech? Specifically, I am looking at using Polk RTi70 towers as my mains, with a Polk CSi40 center. These are timbre-matched. However, for the surrounds I like the Def Tech bipolars, either BP1.2x or BP2x. Would these surrounds work well with these front spreakers? Will also use a Polk subwoofer, not sure which yet.