Back when I was stationed in San Francisco but at home I visited a local "cop shop" and got in a discussion with an FBI agent. He told me to never get a holster which had any kind of added retention device. Open top was the only way to go., He said the part of a second it takes to draw and present from a strap is the time it takes for bg#1 to take you out. He directed that I find a good open top that retains the pistol with pressure from my body and the belt is all I should need. He empathized the retention should hold the pistol without added devices. I have run, tripped, fallen, jumped over or under several objects and have yet to have my pistol dislodge. Yes, the day may come and if it does I'm hoping it doesn't happen on a day or at a time when I really need the gun in my hand. Likely that is exactly when it will happen but then I'll just have to die with air and a prayer in my hand.