The BPPC scsi is fast scsi-2 (theoretical maximum 10MB/s speed). CSPPC scsi is UW-SCSI-3 (theoretical maximum 40MB/s speed).
603e VS 604e?
32bit VS 64bit memory access?
To summarize, comparing CSPPC with BPPC...there's no contest, CSPPC wins. :-)
One of the reasons why A3000/A4000 is nicer to expand than A1200. ;-)