This has been a topic quite often debated and the reality of the sprag or overrunning clutch is simple.Failure is a result of improper use or the result of component failure some where else.When failure occurs elsewhere and a sudden lockup occurs the overrunning clutch usually fails no matter how many rollers it contains,likewize improper use such as Ultra high RPM during a burnout or a high RPM flareup during a component failure usually will cause failure.If your stock overrunning is good there is no need to replace it,if it bad then any of the aftermarket replacement can be used.My take on supersprags is they are a excellent replacement if needed,but be cautious and operate the trans properly.Don't think that it will guard against stupity,it may just be that many little bullits flying out of the case.Dont think of a supersprag as invincible.
Respectfully Bob