It's not about optimizing for speed; it's about optimizing for comfortability. Not having to move your hands at all from the keyboard is highly underrated. If you pair it with a windows manager like i3 and use something like vimium on chrome or zathura for pdf, you always have your hands on your keyboard. You don't realize how great that is until you try it. You can't go back to the mouse.
And if your my kind of programmer, you start to move to programs that have VI keybindings, swap out for ones that do, and hack into the ones that don't to make them do!
