I've got a Gillette Tech (no idea on year or other specifics, I only did enough research to determine it was a tech, it is gold plated but that's about the only specific detail I can provide at this time) it shaves okay as long as I do my part but a few weeks ago I noticed that the blade is slightly wavy when the handle is screwed down tight. It's really hard to see, but if you get the angle just right you can see that the reflection off the edge is kind of a zebra pattern rather than a consistant reflection you'd get from a perfectly flat surface. I looked for the cause and found a couple burrs and nicks under the head, I've used a fine hone to smooth out the edges (and remove even more of the plating) but I can't get the blade to be perfectly flat.
Since this discovery my shaves have been increasingly worse although last night I went back to basics and made sure to pay attention to pressure and angle and got a much better shave than I had been getting. I think my observation is a placebo but it's got me wondering, should the blade be perfectly straight across the lenght of the razor or is some slight waviness common?