Working with the most basic of the minimal holsters/alternative concealment method.
I try to remain open minded until I have been there and done that myself and gained hands on personal experience with a product. You won't see me make a statement like "best ever, or this is the only way." I will state what works for me and quantify that statement with my opinion and findings.
There are a lot of different ways to get from point A to point B, especially in the firearms field, and the way one does it isn't necessarily good for the next. Here is something that I am still experimenting with, but am drawing a favorable conclusion for limited use.
The Zacchaeus minimalist holster built by Dale Frick Holsters is a kydex "trigger sheath" that, while being carried AIWB Mexican carry (appendix in the waistband, sans traditional holster), attaches to the wearer's belt with a nylon cord. The cordage keeps the Zacchaeus and gun from sliding down into the wearer's pants too deeply or allowing it to move horizontally around the waist band.
I have found this method of carry very secure, surprisingly so in fact. With no loss of weapon retention or control. I feel completely secure in carrying this way for casual, non-active activities; running to the grocery store, renting a movie, errands, etc.
I have found my XD service model .40 S&W conceals easily and securely. The weapon doesn't shift anymore than one wants an appendix rig to shift being that some movement is good for this technique when going from standing to seated positions or bending. In fact, except for not having the extra bulk of a holster IWB it feels like the gun is holstered traditionally anyway.
Where this type of rig shines is in carrying off the body in a purse for the girls, briefcase, day planner, pocket carry in a CC jacket or vest, glove box, or nightstand for home defense. This device will keep the trigger covered on a striker/SA fired design, those without external safety like the Glocks, XDs, etc. I don't find this necessary with DA or a pistol with an external safety, but for a machine that goes bang with very little trigger pressure I like it. Especially when half asleep and fumbling for a weapon when you hear that bump in the night and reach for your HD gun. With this product you have something protecting you from negligently pulling the trigger while trying to get a firing grip in the dark.
I like this product. I won't be giving up my leather rigs for it, but it fills a niche and a purpose for me.