The E-6B was developed in the United States by Naval Lt. Philip Dalton in the late 1930s. The name comes from its original part number for the US Army Air Corps in World War II.
I took to the Jeppesen one as soon as I saw it and have not used anything else since, including on my exams, although the small one is kinda hard to read at night. I can also recommend the AFE product as a better precision instrument than the CRP-5
Phil