I have a grandfatheroak for an LCR and an aholster for a G26. It works great for the G26 but I found that the molding at the cylinder edge on the grandfatheroak rubs uncomfortably.
Advantage -could be- thinner than leather or uncle mike's types if the kydex used is thin. Retension is also an advantage as I don't like my pocket holsters to be so loose that the gun will come out when I sit (if my knees go up higher than my waist).