well I can tell you that the Coan super sprag is using the sprag out of a ford c-6 trans and in 25 years in the business I have never seen a c-6 roll a sprag like the stock 727 do and that is because like stated above there are more rollers and there is just not enough room to roll them.
They are the only bolt in sprag that does anything for you other than save a bad case.