A couple of hours into using the new Apple operating system and I can already tell you a few things. The first impression you will have after the update is that nothing changed. Everything pretty much looks the same. You'd think you just spent $20 on nothing. And then you start noticing little things. Suddenly Mission Control and Launchpad, both functions I had previously removed from the Dock, are back again. When you try dragging them off, nothing happens. They're stuck. Thanks to Jason Snell of Macworld for letting me know that I should right-click on the items to remove them.
I dictated a few email messages in Mail. Worked flawlessly, although every once in a while the computer waits for the Apple servers to return the written sentence back (the process of transcribing your words to typed text does not happen on your computer).
So far no complaints yet about Notifications. I like seeing new email message notifications appear at the top right of my screen. I am a bit peeved that my everyday computer, a late 2010 MacBook Air, will not support Airplay Mirroring. My video production machine, a more recent MacBook Pro, does show the Airplay icon in the menu bar, but that one rarely moves from its spot these days.