With or without a light?
Here are my original thoughts on one using a Glock 19 and a TLR-7 light:
https://pistol-forum.com/showthread....run#post789647
However, after seeing what happens with the holsters, during defensive tactics training, I would update that opinion, and say the retention is not adequate. The guns can, and often do, come out of those holsters during "fights." Not someone grabbing the gun, just coming out while two people are fighting.
However, it's a problem with every concealed carry holster I've tried with a light (and many for use with just a pistol). Designs that work great when used where the holster is designed to hold onto the front of the trigger gun, often work terribly when trying to hold onto the various lights out there.
I'm surprised with the advent of small lights, intended for use on concealed firearms (XC-1, TLR-6, TLR-7), rather than duty guns in duty rigs, with lights not originally designed for concealed carry (X200/300, TLR-1), that the light designers didn't get around to creating a notch near the bezel, that would give holster makers a place to have the light clip into securely. It's generally not a problem with large duty rigs, that have real retention devices, as they can be made to secure the light in different ways, such as holding onto the slide at the ejection port (ie, Safariland ALS). It's a huge problem with concealed carry holsters.
However, I will add, most people who haven't trained fighting with a gun in their holster, or actually had to do it in the real world, often keep their guns holsters that are way too "loose" for serious use. So I suppose holster makers, and light makers, don't have a huge incentive to fix the problem, as people are too willing to accept holsters that aren't adequate for holding onto the gun during a violent fight.