I'm thinking about getting a new center channel, currently using a CSi3, and wonder if the CSi5 or CSiA6 is a noticeable upgrade. I'm matching them to the RTi6 speaker, but will likely get a pair of the RTi8's or the RTiA5's in the next year or so. I'm looking for something that will fill my room a bit better. My living room is 18'x15.5'. Will there be a noticeable change in volume/output with the larger 6.5" drivers instead of my current 5.25"? For those of you who made this change, is it worth the extra $$$?