I have two SCSI-2 adaptors (60 and 40 gig maxtors connected) via BPPC scsi. Works great (9.7MB/sec). No reformat needed, I could plug the IDE drive as-is and have full access of the drive. No problemas at all, and in case of SCSI failure I can access the disk via IDE... Pretty cool stuff.
I higly recommend this if you only have a slow IDE.