Over the past week, I think I've had a breakthrough. A confluence of events have taken me to the point where I'm getting three-pass DFS with minimal irritation.
It all started last Tuesday. I had been using Feathers for about a week. I was getting really close shaves with no nicks so I thought all was well. But after about the third day of Feather use, my face was getting extremely irritated. By Monday morning, event he shaving cream stung. It looked so bad aferwards that I didn't even go to work. I tried again on Tuesday, and the result was only slightly better.
So, on Wednesday, I switched out my Feather and went back to the Wilkinson Sword, which had been my original blade before experimeting with Crystals, Derbys, Astras and Feathers. I also felt that my blade angle may have been off. So I did some reasearch and found the best possible advice. Hold the razor handle perpidicular to the face and lower it 30 degrees.
The combination of angle adjustment and the Wilkinson Sword blade has made a huge difference. My shaves are smooth and my face is burn-free. At some point soon, I may try a Feather again, but I say this: Feathers aren't for everybody.