I’ve been using XS Sights Express Sights on my handguns for many years. They are easy to see in any light, fast to acquire and rugged. They are also great for teaching new shooters because with express style sights shooters are less likely to try to obtain that “perfect” sight picture which is not needed at defensive handgun ranges.
I also have XS Sights‘ aperture sights on a lot of my rifles and in fact, when I travel to Mozambique this August, the Marlin 1895 SBL I’ll be using for buffalo is fitted with an XS Lever Rail and aperture sights. (They will be my back-up sight.) My primary sight for that rifle will be a Leupold Custom Shop 1-4X Scout Scope. I’ve zeroed both the sight and scope for 75 yards which should be about perfect for any buffalo who thinks I owe him money.
For those who believe express sights on a pistol is a bad idea, its kind of like trying a new food; you’ll never know unless you give if a try. Most that do learn like I did.
Maybe you should read what Sheriff Jim Wilson has to say about Express Sights.