I used one for my Glock 43 for about 9 months. Great concealment and kept my pistol with me when I wanted it (always). I would say it is a very slow draw though. In addition to having to lift the flap, the pistol is held in a position that is hard to grip when you grab it. You need to pull the pistol out a little and then re-grip it in a better shooting grip. I never needed it in a hurry, so my complaint is a practice problem and I know that adrenaline might change this.
I stopped using it because it did not survive my dumping the motorcycle one day. I slid on my side and the nylon holster got ruined, as did my jacket and slacks. The bright side of that is that the holster did its job and there was no damage to the pistol and no road rash or injury caused by landing on the pistol.
Overall, I recommend them as a good way to carry a small pistol. A little slow to draw but much faster than an ankle holster.