Perhaps those with current experience can enlighten me; what are the advantages/disadvantages of the rear iron sight in front of or behind a mini red-dot sight. For example, I have seen Glock 34's with a Trijicon RMR in the rear of the slide. Some have the iron sight in front of the red dot and some behind---that is what I am asking about. I have not been in a handgun competition of any kind since Brian Enos was the champion!