...and then again we have the "poncho raincoat". I tend to use a poncho raincoat on occasion, especially for drizzle and such.
In reality, though, I use a sports umbrella the most. If I get caught in a storm I'm not looking through my pack for anything. I'm using one single button to have an instant cover over me. I always use a sports umbrella because it becomes a "roof" to hide under. I have on two occasions sat down in a safe place and covered myself with an umbrella until a storm passed over. When canoeing the umbrella is fixed to the side of the pack for immediate use. In this neck of the woods, I've also used an umbrella during a snowfall.