I won't use anything but lined holsters on my highly polished blued guns. The chemicals used to treat leather can be corrosive , especially when damp from humidity , even on stainless guns.
Suede used in holsters is usually treated with silicone , and I always retreat my holsters with a good grade of silicone spray often. I've had some beautifully blued gun including my Python , in suede lined holsters for a long time with no damage. And yes , they do feel smoother on the draw.