The RTi12s are awesome speakers, I'm just saying I like the Def Techs a bit more because their bi-polar design creates an incredibly detailed musical sound stage. In other words, they throw out a holographic dimensional sound, where each instrument and voice can be located in space. My Polks give off a beautifully detailed sound, where louder is better. In no way should you consider yourself "stuck" with the RTi12s. Give them enough juice, 200+ watts, and there's nothing in their class that sounds better. Keep your CSi30, it's fine. Either center will get the job done, you wouldn't to be able to tell a difference between the two. I watch TV in my bedroom with l & r speakers only, no center, and I can't detect the absence of a center...they create a very believable middle channel, so no need to obsess over the perfect center.