I recently (last week) got a IWB holster from old faithful holsters. It is super comfy and comes with all the hardware necessary to adjust the tension on my glock 19 in the holster. As the holster breaks in I can already feel it loosening up. How tight is your gun in your holster? Give yourself a wedgie when you draw? Smooth like butter? Can do a headstand while packing?
I like for mine to stay put when turned up side down. PS Ya don't have to stand on your head. Just take off holser, and turn it up side down.
Hey we all have our things...
I ask because adding the belt does make a difference. When I put a full magazine in I can get it out no problem by shaking. I suppose that if I am ever being shaken while upside down I have more problems than weapon retention.
Depends on the personal level of comfort. It is always a tradeoff between draw and retention. Too tight defeats the ultimate purpose of carrying. Too loose sets you up for a public embarrassment or worse. Body habitus, lifestyle, risk assessment, the type of handgun carried, all need to be considered by the individual.