Negatives = No RAM expansion & No DMA
Positives = IDE allows use of cheap IDE drives without an expensive adapter. Still in production.
That was one thing I was wondering about. My A2000 had an 040 PP&S card and a A2091 SCSI card installed. The A2091 couldn't communicate with the 040 via DMA or some such problem, and therefore hard-drive transfer rates were abysmal. I upgraded the ROM on board the A2091 and then bought a GURU ROM, and this improved the situation somewhat.
But if the Buddha can't DMA to accelerator card RAM at all over the Zorro II bus, then that's going to mean pretty slow transfer rates, no? PIO mode on the A2000 was very bad with the A2091 as I recall (something like 50Kb per second or similar when I last experienced it).