I love my DE razors for all the reasons everyone here is familiar with, and find the constant "improvements" in cartridge razor amusing since I have the option of bypassing the hype.
I have in the past while come to be annoyed by the "progress" made in the area of toothbrushes. Every time I get a new one it seems to have more "features"; angled bristles, tongue scrapers, squeegees, extreme angled heads, vibrators, lights, timers etc. And most of them won't even sit on the counter without rolling on theirs side and getting toothpaste everywhere. See where I'm going? Toothbrushes are on the same track as razors. The more they improve the more useless they get.
Yesterday I was in a health food store looking for some vitamins and I came across Fuchs natural bristle toothbrushes, what a revelation! A toothbrush, plain and simple, like I remember as a child. I bought a couple (they were cheap!) and actually enjoyed brushing my teeth last night and looked forward to using it again this morning. Truly the DE experience applied to teeth!
I have an Oral-B electric and the difference between teethbrushing and shaving, and where it breaks down as far as I'm concerned, is that we don't have doctors (I guess dermatologists?) definitely stating that shaving with a cartridge is better for you than DE shaving. Every dentist I've seen, or oral surgeon (I've had a bunch of gum surgeries), or dental hygenist has told me that, unequivocally, an electric toothbrush is better than a regular one. And they all say that a soft brush is better than any other. I have no idea how "soft" a natural bristle toothbrush would be, but since they're boar bristles, they cannot be that soft.