I have been around firearms since I was "knee high to a grass hopper" and I have never seen or experienced the effectiveness of picking up the sight picture more effectively and quickly than with diamond sights. I have them on a Sig P239 SAS 40.
I guess if you're home alone this type of open sight may be effective. But in public open sights are too intimidating, tacticool, and embarrassing. Got to cover them up or folks will get nervous around them.