My impression from reading the book was that it had a beautiful internal architecture that I imagined would largely be hidden from the user. I think as a say COBOL programmer on an AS/400, one would pretty much see it as not much different from say a mainframe. This opinion is entirely formed without experience though.
It's still very different from a developer/"system user" perspective (I don't say enduser because then you are kept away from most anyway). A lot of concepts one takes for granted are different.
