If you don't want to the holster material to rub the finish and wear it off, I also agree that Kydex or one of the other wonder materials is the way to go. On the other hand, if you want your pistol to develop a working gun's patina, then leather will help do that. I personally have not found a Kydex holster, IWB or OWB that was as comfortable to wear as a leather holster.
Its your carry gun... let it show it! All the other guns will be jealous that THEY don't get to go out on your hip and have the same worn/used/loved look to them.
^^^^ There ya go. If you want a collector quality safe queen, leave it in the safe. It's about fighting with a gun on which your life may depend. The finish and any honest wear on it is so far from meaning anything that you need to purge the entire train of thought from your head.
Looking for a iwb and possibly later a belt holster for my m&p's. Is there a material or brand that will keep the slide finish looking clean and not worn out? is it even possible on the m&p finish to wear out? Thanks.