There’s a lot of research in this area. One of the most consistent results of this research is “people don’t feel like moving their hands (off the home row, over to the arrow keys, over to the editing keys, etc) is slower, even though it is slower”. For most people, the feel is more important than the speed.

In other words, this argument topic usually doesn’t end reasonably for either side. :-)

P.S. For extra fun, look up the mouse-vs.-hotkeys discussion. My favorite example is in the research paper for Plan 9’s Acme & 8½ ui.