I'm currently running an Onkyo 595 receiver with 4 Polk R10 speakers and a CS175i center channel. I went with these because frankly, they were cheap and I liked the sound of the silk dome tweets at the time. When I was auditioning before I thought Polk's tri-laminate tweeters were way too bright sounding with my noisy JVC receiver, but now that I have the 595 I feel like maybe I should have gotten the tri-laminate tweets. The CS175i just doesn't quite hang anymore (especially at volume) and it seems to image more to the right (perhaps because it only has one mid-range), but if I replace it I guess I'll be replacing my mains as well so that the three fronts will be timbre matched. I'm considering upgrading to the CS245i center channel and RT25i mains. I'm looking for any opinions regarding whether I should upgrade, specifically: 1) How do these speakers sound with the Onkyo? 2) Do the tri-laminate tweeters mellow after some break-in time? 3) Will the 245i be significantly better than the 175i? 4) Will the RT25i's be significantly better than the R10's? 5) Is the sound so different that I should upgrade the surrounds as well?