@victorjs - Considering your primary use is for HT movie watching, I would stick with the old advice that says you should have all speakers voiced the same. To me, that would mean stick with the CM series, as your rear speakers and center channel are from that series. Getting your 5 speakers (Fronts, rears/surrounds and center) to be voiced the same would be a good goal. Are your center and surround S2 models in the CM series?
If your primary goal was 2-channel audio, I might offer different advice. But considering you are primarily HT, keeping all speakers voice the same should be a focus.
If your primary goal was 2-channel audio, I might offer different advice. But considering you are primarily HT, keeping all speakers voice the same should be a focus.