I have the FB, Slim, and several other vintage Gillettes. Love 'em all. I tend to use a razor for several weeks (or months) before swapping it out for another one. Once I get used to the weight, balance, geometry, etc. of whatever razor I'm using, they all basically provide the same result. Every time I swap razors, or even blade manufacturers for that matter, I need a few shaves to settle in. I keep my adjustables on 9 and work from there. Any setting would do, although I think the lower settings take more getting used to since the sweet spot is narrower. To me, it is a matter of establishing the correct blade angle against a flat (stretched) portion of skin, using correct pressure, shaving in the right direction, and having a properly hydrated skin surface...regardless of the razor I'm using. A DE razor blade is gonna cut hair (and hopefully not skin) just fine, but it's up to me to position it correctly if I want the best shave. That's my story, and I'm stickin' to it.