I have been actively using a Clipdraw for years on my Glock 17 (and my wife has one on her Glock 19). I can’t really think of a simpler way to carry a pistol on your waist that will hold it in place (queue the comments about duct tape).
The only place I think it falls down is when exercising. Attaching a gun (holster or Clipdraw) to ranger panties is a recipe for an indecent exposure charge. For any other situation, I think it works. You don’t have to worry about threading it on a belt (it can go over or under). If you need to relocate it, you just move it.
One of the things that is new since I bought mine is they now have an adhesive based attachment for the clip. The one I have (and they still make) has a replacement butt plate on the slide that the clip can screw into.
This year they have models for the new Glock, and are soon to be coming out with one for the XD-S (which I will definitely be buying). The other new variant is for 1911s. They can now accommodate an ambidextrous safety (due to a little cut out on the mounting plate).
If you are looking for a simple and easy holster, I highly recommend them. For updates, you can like them on Facebook or follow them on Twitter.