I'm not happy with any blade that won't happily 'pop' arm hairs. It's not just a csae of shaving them off, it's having them 'pop' off the skin as you cut them, almost as if they were leaping out of the way before the edge gets to them. I consider an edge to be truly sharp when it will easily 'top' those same arm hairs, cutting them cleanly without the edge touching the skin.
I like all my blades to be at least shaving ('Popping') sharp, from small folders, through the larger fixed blades, and even my axes.
Edge geometry differs between applications of course, but sharpness and geometry are different things altogether.
I figure that given enough work to do ANY edge will start to dull after a while, whatever the geometry, whatever the steel and whatever the heat treat. If I start to work on a job with a knife I want to finish that job long before the blade becomes dull. If my knife (or axe) is, say, 10% sharper than the next mans, and we both do the same amount of work then if the knives are equal mine will still be 10% sharper at the end of the job. This will allow me to do the work easier because I'll be using a sharper knife all the while I'm working.
In essence, the sharper the tool, the easier the work, and the longer the tool will remain sharp in use.
Just don't be tempted to make edge too thin in order to achieve 'sharpness' as edge damage will become a negative factor in the working efficiency of the tool if you do so. You can achieve a truly sharp edge AND retain enough strength in that edge to prevent undue damage by getting the edge geometry right for the tool in question.