FWIW, I ride fixed for long distances and have never been comfortable on any leather saddle. I like to move forward and back a lot, since I can't shift gears, and leather saddles one way or another have a rail across the back that is no good to back up onto and sit on.
My favorite combination involves a saddle that isn't produced anymore (I bought extras back when it was though... aside from being a favorite though, it's nothing special - modern, plastic, etc) with a neoprene cover on it, mostly to cover over the cutout. But the neoprene does add a bit of padding too, without making it too deep or squishy. It comes out just right, at least for me.