There is another little point here - SCSI can have up to 7 devices connected, when an IDE port can have but 2. This may make a difference depending on needed configuration.
However - I have used both SCSI and IDE in my old A2000, without any real troubles. It was a 68030 GVP accel. with SCSI. Sure it slowed the system down some, but it was still very usable.
