The type of holster matters more to me than the gun. I prefer a strong-side hip holster with zero cant and only friction for retention. That type of holster works well if I am in a normal outdoor situation or walking around in town with a coat on or even with a long shirt tail pulled out. If I might find myself running, crawling, climbing through heavy brush or under or on top of machinery, or falling in slopping mud, I want the option of a retention device. Slower yet, if neater dress and deeper concealment is required, I might have to go to an inside the waistband holster or a pocket holster.
When the country gets especially rough or I find myself in a canoe or a kayak, I go to an El Paso full flap crossdraw holster with a canteen snap. A few years ago I took a solo trip down the Kongakut River in Northeastern Alaska up next to the Yukon border that called for hugging a section of Arctic Coast before I came back to a town. The river was more suited to rafting than the nylon framed folbot I used, and I faced the real possibility of losing everything I owned except what I had on my person as I floated out to shore. I wanted a holster that had the best chance of retaining my Smith & Wesson 629-1. Even that holster was not as slow as I would have imagined after I practiced with it for awhile; albeit, the faster draw required two hands, never a good thing.
I agree with the idea that a person would be better off if he could carry exactly the same gun in the same holster all of the time, but I'm not sure how I could make that work unless I chose something like a J-frame Smith, and as much as I love pocket pistols, I don't feel nearly as high on the food chain with a small gun as I do with any full-sized belt pistol.