Yes, the S3/5, even at 84dB/w sens will get pretty dynamic with the Rotel. For greater extension and slam you should look at the 88dB bigger (6.5", 165mm) S1/3P, or even the now-discontinued great SC3 center channel, turned sideways.
It's exactly like a double-woofer S3/5, also at 88dB, vented for deeper extension. Both options list for $1400/pr.
Any of these three Spendors will have a more honest midrange and more forgiving top end than any B&Ws. Warmer than the Triangles, too, if that's a reference you know....
