Many straight razor aficionados and users unfairly look at stainless steel straight razors as second class. But the differences to non-stainless carbon or standard steel can be minimized by the right choice of steel and optimal thermal treatment by the manufacturer, and even a few specific benefits achieved. According to the Deutsche Industrienorm (DIN), steel may be labeled "stainless" if it contains at least 10.5 % chrome. Even steel labeled "stainless" can rust if it is used improperly. Improper use in this sense would be, for instance, leaving fruit acids on the blade after use.
However, dry wiping the knife is sufficient in most cases to prevent the formation of corrosion. Experts outside of retail thus usually (correctly) speak of "rust resistant" steel. For the sake of accuracy, we will use this term going forward. In order to get a rust resistant blade, the addition of chrome in the alloy is necessary more than anything. Chrome also has the property of making the structure of the steel coarser, sometimes significantly so. This is not really wanted for a cut under pressure, as required by a wet shave. The difference can be seen under a scanning electron microscope and looks dramatic, but can hardly be felt in practical use. In return, you get the invaluable benefit of rust resistance. One limitation is that straight razors with rust resistant steel are somewhat unsuitable for beginners. Due to the fact that rust resistant steel is comparatively more brittle, it reacts worse to wear and deformation. Even if rust resistant blades can be similarly sharpened overall, the stropping and grinding requires a bit more practice.
Rust resistant straight razor blades achieve their full potential if they are pushed over the skin with a very slight offset, i.e., sliding sideways ever so slightly. The minimally coarser edge then develops a microscopic sawing action. However, only very experienced users should apply this technique since it requires lots of practice to master. In conclusion, we can recommend acquiring a rust resistant straight razor to practiced users for traveling or everyday use when in a hurry.