craigd
Yes, Steve's micro graphs are great and really help me visualize the abrasive wear that Larry has talked about. I still don't have a grasp of the actual scope and wear rates - eg how much honing do I need to do to remove that wear on the back? (I have one of the fine loupes that David recommended, just need to start using it).
I just took a look at the #3 blade I've been using, there is a very visible wear strip on the back, if it actually changes the bevel angle, I really doubt I would be able to tell when using the plane (I regularly push 45º to 60º planes without noticing much difference in effort).
I probably should have emphasized that I only do this for double irons, if I have to pop out a single iron, the back side gets a swipe or two. I'll also admit to not caring that much about nicks, etc; no tearout and I'm happy.

Regarding the ruler trick & chisels, depends on the chisel and use - my gouges have a massive back bevel (as they are bevel down (can't remember which cannel that is)) and chisels are used bevel down.