As far as hanging vs traction stretching vs all day stretching in grams of force, there is no proven study (Ii've ever seen) of what works best or is more effective for gaining length. Some guys swear by hanging, others swear by traction stretchers and others swear by ADS. When traction stretchers were the big thing, many people swore by them, however there were other methods that worked better for other people.
ADS and weight hanging has been around centuries before traction stretchers. The original reason traction stretchers came into play were for straightening curved penises. Traction companies started marketing traction stretchers for penis enlargement to capture another audience.