After a year of cold water only lathering and shaving I have turned on the hot water tap. Yes I had hot water but just decided that I wanted to explore cold water shaving. The first hot water shave found my boar brushes much more flexible and happy making lather. My face and whiskers hardly noticed but building a good lather was a lot easier. My impatient day DE razor rinsed cleaner and might have slightly better glide. Open blade str8s seemed about the same. But since I am a fan of "latherin" I think I will stick with the hot water for lathering. All good shaves begin with a good lather.