Speaking from personal experience, a taller front post is nice if you find yourself backing the stock one all the way out to get a proper zero. On a standard front sight assembly, you'll probably not need the taller post. However, on some aftermarket flip-up front sight assemblies, a taller post may be needed. I have a PRI front sight on one rifle and I definately needed a taller post in conjunction with my ARMS 40-L.