on XD40. Both my sons and Mrs RiverRat use those for carry, never had a FTF or any other problem. They just work.I can't argue about Glocks, have never used one, but the grip and pointing were not to my liking. Sure it's a safe bet, too.
I would suggest that you take one of each out to the range and see how they fit your hand and point of sight.....pretty sure that'll make up your mind pretty quickly. GL