QUOTE
7. Inconsistent User Interface. Open iTunes, Safari and Mail. All three of these programs are Apple's own, and they're among the ones most likely to be used by Mac OS X users. So why do all three of them look different? Safari, like several other Apple-made apps such as the Finder and Address Book, uses a brushed-metal look. iTunes sports a flat gun-metal gray scheme and flat non-shiny scroll bars. Mail is somewhere in between: no brushed metal, lots of gun-metal gray, and the traditional shiny blue scroll bars. Apple is supposed to be the king of good UI, and in many areas, it is. But three widely used apps from the same company with a different look? Sometimes consistency isn't the hobgoblin of little minds.
It's not that it looks different that bothers me (not much anyway) but if it "works" differently that might tend to hack me off; not sure I could name an instance of that but I feel like I've run across them.
I also think the gig on printer setup is correct in a way because we have an accumulation of printer configuration methods with Bonjour, Appletalk, Windows Printing, IP Printing. . .but that's not the fault of the operating system. Maybe a button that goes out and finds all the printers that can be found irregardless of the method used to find or attach to them. MAGIC!