I have the Flash Bang for my Kimber Solo. Honestly, I struggle with it. I'm a 36 A and even with a with a VS Bombshell bra (which is padded like crazy) I can't mange to get the stupid thing to stay put. I think it's a great concept and ladies that have larger busts may have better luck. I wear it when I absolutely have to, but I am constantly re-arranging due to slippage. I'm having pretty good luck with my belly band. I find that I can use it wearing just about anything. Skirts, jeans, yoga pants. I have my eye on a corset holster. Pretty much the same concept as the belly band, but geared more for a woman's shape.
Thanks for your input! Im 42DD and worry that it will be uncomfortable. I guess I should just buy one and try it and have a cc purse as a backup. I'm not sure about the belly band but may research that too!