My sharpest razors are carbon steel, but my stainless razors are just a tich behind. Stainless razors came along fairly late in the game, which means they are all consistently high quality steel and manufacture. My carbon steel razors run the gamut from "C" to "A+", but my stainless razors land between "A" to "A+".

Stainless razors are a bit harder to hone (especially vintage because they've been so neglected) but aren't any harder to keep going once they're sharp.