I use a Remora holster for my XD40 I also have a De Santis Holster but havent really used it to much because I like my remora so much.
I have around 500 - 600 rounds thru this gun and yet to have a malfunction.
When I conceal this gun, I normally switch out to the smaller mag for better concealment.
I also like the fact is that you can switch out the barrel (aftermarket) and shoot another Caliber. (I've only read about this and dont have first-hand insight).
But it's a nice feature