According to Dave Haynie, PCI was/is better than Zorro (3?), and they might even have switched to that given time.
Actually, what Haynie said on the TeamONE ML was he dumped Zorro IV developement for PCI since it was now industry standard and was on par with Zorro IV. Many reasons why Amiga had exotic interfaces/buses was there was not truely decent standards to follow back then.
Dammy