Hello,
The Apollo SCSI controller is not as good as the Blizzard one (not fast SCSI, not DMA). I think it will not bring much more than the onboard A1200 ide controller, unless you would like to connect easily external drives (CDrom drives or hard drives) to your A1200.
AFAIK, I have an Apollo1230 board and I don't think I will add the SCSI controller. But if I had a Blizzard 1230 or higher, I would certainly have considered it.