Well, since VOL called me out on this, I guess I'll tell my horror story.
I bought one of these to carry a S&W MP 340 (small revolver) when I was wearing sweat pants or something that didn't allow for a good belt carry. I carried it a bit higher than JL mentions and enjoyed the ability to wear a light weight gun around all day in shorts or whatever without issue. I was at the baseball park with my son's baseball team helping coach some of his teammates at the batting cages. I had them hitting off of a Tee so I was constantly bending over to pickup the ball and place the ball back on the Tee.
I bent over one too many times and the revolver dropped out from under my shirt and hit the fake grass covering the concrete floor in the cages. I saw it coming out and everything went into like slow motion. I grabbed the gun just as it hit the ground and shoved it in my pocket. The kid hitting never saw it and there was no other children around but his Mom was standing there and she saw what happened. She didn't say anything to me but did talk to the Head Coach and he later asked me to make sure it didn't happen again.
I have never, EVER had anything like that happen in almost 20 years of carrying and I haven't wore the belly band since. Again, in the defense of the belly band, it was a great carry option and I possibly was wearing it too high and the bending over action, over and over, caused the firearm to come out. The belly band also came with a velco snap that would have given some additional retention but I thought it was too hard to manipulate quickly so I removed it when I wore it.
Ever since that has happened, I can't bring myself to try it again as I'm too scared of what might have happened in that scenario.