The SMS-1 does not do anything for full-range speakers - it is a subwoofer equalizer.

As for why you are hearing a difference between the CC-470 and CC-370, I can't say. I don't have either speaker, although my Studio/CCv2 is probably similar to the 470. There are several possibilities, certainly. The 470 may have a different tweeter, different crossover network, or both. The results could be an accentuated high end, which some people don't find to their liking - especially if the room is a bit live (hard surfaces and the like). I recall that my Paradigms clearly benefited from the addition of an area rug after we removed the wall-to-wall carpet and refinished the hard wood floor of our old living room.