I just received my CTAC IWB holster. Any Glock 9mm or .40 S&W will fit in this holster. It is very comfortable and conceals well. Below are some photos. I do not plan on tucking this holster unless I am wearing a suit without a jacket. But I included the picture just so you guys could see.
What is underneath, G23:
There is a spare mag in my left rear pocket next to my Surefire E2E.