I have a MK III Hunter. Love the gun; hate the sights. I replaced the front sight with a black, square post. I replaced the V rear with a VQ Bomar like rear. I loctited both securely in place and havenít had any problems with them. I also did a few other things like replacing the sear with a VQ sear, replaced the hammer with a VQ MK II hammer and bushing, replaced the trigger with a Marvel trigger and drilled and tapped the mag release and added a 1911 mag release extension. No more mag safety and a long enough mag release that I can reach it without shifting my hand.
If you like the sights, consider Loctite. I like the red stuff for sights.