I have been looking at front sights and i see that S&W make 2 types of front sights. The pinned ones and the DX type sights. I understand how they both work but i dont get why they still have both types. Do the pinned tend to come on the "defensive or hunting "guns and the DX on the competition type guns? Is one system going to replace or phase out the other system? What do you guys think, is one better than the other?