Interesting opinions of each. Over engineered box cutters, worlds smallest survival knife... It would appear that the Nav. would be a great little knife for every day carry, as would the mouse, but the mouse would put up with more abuse because of its more robust blade. How comfortable are the cut-outs in the navigator when you have to get down to work? How durable is the almite finish? The reason all the questions, I have a co-pilot I love, but want a similar size knife to replace it with. Also I like the shape of the mouse blade, reminds me of the old hunter, or executive models.