My biggest gripes are around Spotlight. Have you ever tried to search for a file or or create a smart folder that works? These features are horrendous. And Cmd+Space [type app name] used to be a decent app launcher. These days I often find it sits and spins and I end up using the Finder and navigating to Applications -- and that's faster than Spotlight.

When I actually need to find a buried file, I drop into a terminal. Then I feel sorry for people who don't know how to do that.