I now have a pair of the CTS/Motorola KSN1188a motors, and 5x15 lens. The answers to my questions in the above query are yes, they are smooth enough for home stero, and they will take the abuse of PA use.
Like other piezos in the CTS line, they seem to be more efficient than the published figures. When teamed with a 97db/wt SPL 15" woofer, the KSN1188 sounds very natural.
I will continue to tweek this setup, likely biamping the system.