TomD
They should be hair popping sharp, which means that when you shave your arm, you should see some hairs popping way off. I don't know that it is consistent for all hair types but you should see it sometime, if the edge is xtra sharp. The first step in hair sharpening on stone one is normally to feel for a wire edge. This works great but essentially requires oversharpening through the grit.

There are better ways though. One is based on just going through the process if you sharpen your tools through the various grits, you will get the results you want. Of course you don't want to have to work blind, so I use two test that have worked for barbers through the ages. You sharpen on your base stone to get rid of the initial dullness. This step forms the initial acute edge but does not polish it. When this needs testing you lick your middle nail, and press your finger and thumb together for stability. Then you take the blade and with the edge facing you and at a low angle to the nail you see if it will catch on your nail. This is non-destructive, and can be repeated all the time. This way you can examine the edge to see if the first stone has done it's work. Once you are sure you are done with the first stone, you go on to the next. Once sharpening on the second stone is done the edge should be razor sharp and ready for use. One performs a similar test this time on the tip of a wetted finger. If the edge catches it is razor sharp. This test is normally done with a razor, so care has to be taken when doing it with heavier, and various shaped tools. It isn't so much the testing, it is the swinging into place of the tools, or the dropping of them. I haven't ever had a problem, but maybe some close calls.

For normal work a two stone resharpening process is fine. But if you want to use a whole lot of stones (for the resharpening process, all methods use at least one other stone for basic shaping and taking out of chips etc...) then the two stages method falls apart, neither the finger method, no the hair method is sufficient. To use multiple stones one really needs to use optics. Since using extra stones is not going to hurt anything, one may be of the impression one is really getting it done, but it is hard to prove.