I owned a KSA-200S and upgraded to a FPB300. I thought it was no contest in favor of the FPB. Compared to the FPB, the KSA sounded undymanic and sounded rolled off at the frequency extremes in my system. The FPB sounded so much more natural at every frequency. The bass of the FPB was just as tight, but much more nimble.
YMMV
YMMV