I was looking more to the 
 Maxpedition sheaths   than to the waistpacks  : they seem to extensively use velcro : for  belt attachment, for size ajustment, for closing system (that's what I can guess from their web site pictures).
I was wondering what the life expectancy was for all those velcro pieces....
Maybe it's O.K. if you don't "play" with them everyday (i.e. put  the sheath on your rucksack shoulder strap and leave it there ; and put your flashlight in, that you don't use several times a day)