Actually, for my purposes, I disagree. I see Aperture as a robust database for image management. How it handles versions is a real strength of the app. It has other wonderful features too. Its image editing tools, though handy, are not on par with those in Photoshop.
I think for Aperture to succeed as a true workflow solution for professionals, Apple will need to find a way to incorporate the option for Camera Raw editing into the environment, allowing us to import back 16-bit PSD files into Aperture.