I’ll offer that if you have soft water it make no differenceand is purely a matter of preference. Certainly a subjective issue, so allow me to inject another “fly in the ointment”. Consider hard water if you will. Having greater mineral content in the water leads to several different issues such as the formation of soap scum and spotting. Hot water tends to have a higher mineral content if you have a water heater…especially an older one that hasn’t been flushed in a while (running the tap for a minute or two helps mitigate this and should bring the hardness closer in line to just running cold). That said, we all know how hardness is a lather killer, so I offer the following. When rinsing with “hard water”, the soap/cream on the razor reacts with the hardness and forms soap scum; regardless of hot or cold, BUT, as hot water evaporates it quickly dries the razor head and blade as you are approaching the next pass. A drier razor head along with build-up can lead to skipping, especially after a few days of shaving. It’s my opinion that this skipping is often blamed on the blade losing its edge, but most likely due to build up (mineral, scum…pick one) on the blades coating. Of course, this is going to occur regardless of a hot or cold water rinse, but I believe hot water accelerates the process. Having hard water, it’s my preference to rinse my razor in a sink filled with water warm that has had some soap or shampoo added to it. The soap in the water reduces the surface tension of the water and helps keep my razor clean and slick.