The cache (up to 512k if you have the right chips) is said to work, but that is all. Under A/UX you got improved scsi with DMA plus cache.

It was designed with a view to improving performance of the AWS95 under heavy Appletalk server use, presumably involving the kind of small files mostly in use when the AWS95 was new and all the rage. There is a document somewhere showing remarkable increases in throughput with one of these installed.