I installed some Dawson sights (black rear/FO front) on my M&P 40 used for range, IDPA and steel competitions. I really like the sights versus stock, but I'm wondering about my decision to go with a .135" rear notch, /115" front post. I find I like the additional light available on either side of the front sight from the standpoint of front sight acquisition, but I feel as though the larger gaps are actually slowing down sight alignment in the vertical.
This is clearly going to be a very individual aspect of shooting, but I'd be very interested in others' experience in this area. I'm probably going to order a .125 rear sight in any event.