I've been running a Comp-Tac Infidel Ultra for my S&W Shield for a couple months now, and wanted to let everyone know what an excellent piece of kit this holster is. As IWB holster, it is a leather/kydex combo in the spirit of the Comp-Tac MTAC and the Crossbreed. The leather back is not as wide, and the holster secures with a belt clip attached to the kydex holster. It is very easy to secure and remove, and is designed for people that frequently move through non-permissive environments. I carry this holster paired with an Ares Gear Ranger belt, and it is so comfortable that I barely remembered I was wearing it during a recent six-hour wait stint in a hospital waiting room. Highly recommended.
While I normally run this holster strongside, I have experimented with appendix carry. It is very comfortable up front, but the cant on the holster makes for a slightly awkward draw from appendix. If I really wanted to run this rig in appendix, I would have Comp-Tac custom make it with zero cant, and probably trim the bottom edge of the leather.
Also, there was an issue with the original order (my wife selected the wrong weapon), and Comp-Tac customer service was EXCELLENT to deal with.