Good post Phil but it's not just about getting any edge, the edge has to be hard up against the cutter top plate and side plate.
Instead of edge look for "glint". A edge can form on a cutting edge without it necessarily being in the right place. This is why using a finger is not ideal for assessing sharpness.
In the RHS magnification the edge can still have an edge and your finger can still feel an edge but it is not in the right place and this cutter will not cut as well as the LHS cutter. The thing to look for is "glint" , if you can see glint, the edge is not in the right place. Keep sharpening till your see no glint - the edge should look black. In my home shop I wear head magnifiers to make sure I have no glint.