I just tested a DeSantis Nemesis pocket holster as an IWB at 4:00 position. No undershirt, just my shorts with belt and skin with tshirt (my normal clothing). I did a series of draws, including walking around the store a bit and drawing, and reholstering. The holster never budged and top never collapsed to make reholstering difficult. It retained the level and cant I set it at. What I like is that you can adjust both at any time without messing with clips. I'm no expert, but for the limited times I'm away from home and carrying this seems a good option.