You will get more midrange from the 60s due to the multi-driver setup, and obviously more bass as well, but with a good sub, that bass is less extension is somewhat less of a benefit. An ideal match would be identical driver arrays so the 60s would technically be closer to that ideal, but both should be perfectly timbre matched to the center, as has always been the case with the Paradigm lines.
The Sub12 may be a good sub (I am not familiar with 'digm's current subs), but for the money you can often get a lot more sub by going to a internet direct company like HSU, SVS, Epik, etc...