I carried my 642 in a Galco ankle rig for about 5 years and now carry a 442. I changed the rubber grips to wood because the rubber seemed to hang on my pants. There are no disadvantages of either one. I bought the 642 because I knew it would be an ankle gun, and didn't want it to rust. When I realized that the 442 wouldn't rust either, I traded the 642 for a no-lock 442.