Don't get me wrong, my favorite razor is my AS-D2 with Kai or Feather blades that I use 5 times. But tied for 2nd place is my Parker 24C or 63S with either a quality blade like a Voshkod, Nacet, Bolzano, etc that I use 5 times ...or a Treet carbon steel blade that I buy on sale and use once.
My favorite Treet blade is the famous "black" original one. I think it is just about the sharpest blade around THE FIRST TIME IT IS USED. There is also a vicarious thrill in discarding a blade after only one use. I can tell that my 2nd,3rd shaves are not as good. Also carbon steel (shades of the old days Batman) will develop rust spots after a few days.
I have an average beard, I shave daily using a glycerine soap prep, 4 passes WTG, 2 XTG, ATG, alum and an aftershave. And of course YMMV.