I have found that really hard to quantify. The only way I have been able to come up with any useful information is side by side comparison of knives.
I once did a side-by-side comparison between an M-2 AFCK, and ATS-34 AFCK, and a CPM440V Spyderco Military. On paper, you would expect a big difference, but I cut hundreds of cuts on hardwood with each blade, and never got to the point where one was obviously cutting better than the other.
My conclusion: all premium knife steels, properly heat treated, hold an edge great.
If you have a job that you regularly do, like field dressing a deer, you can establish a baseline for that job. But generally, you just have to go by your own comparisons, and those of other owners and knife makers.
I generally don't carry a sharpener with me on a daily basis, but I do sharpen after any day when my edge gets a lot of use. How dull the blade gets depends on what I run into, otherwise, I generally touch up after every day that includes some use that is adequate to impact sharpness. I like my edges to grab at my skin with very light contact, so I touch up the edge after any day when that goes away on a significant portion of the edge.
Harv
[This message has been edited by Steve Harvey (edited 03 August 1999).]