I have spent the better part of the last number of years trying to keep my hands ON the keyboard and AWAY from the mouse. This will allow me to do that in interesting new ways. I actually hope they make a full size external keyboard with the same functionality.
I do concede that there are some good uses for it though.
When your hands are on the keyboard are you looking down at them to see where you are typing? Now you are going to take your eyes off the screen and see if the touch bar has something useful for you. I would imagine you are going to keep using the same keyboard shortcuts that you have used for years.
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But seriously though, I kinda hate it but also think it could be useful in certain situations. Not sure what to make of it.