I'm a fan of the KISS approach, and minimizing the variables.I just shave with them. If I like it, I'll try them in my other razors to see how they do. I don't keep blades that don't work well in all my razors. Too much trouble remembering which one to use in what razor. I give a new blade 4 shaves as that is my typical usage for my blades. I will keep my soap and brush the same as I switch to other razors to eliminate variables.
I've got a dozen or so shaves on a Feather blade right now, and it's still kicking. Blades tend to last a pretty good while with me.