I use a lot of them, especiallywhen fishing for halibut on fly gear... You need to get deep fast and the thicker and heavier fly/running line just slows that process.

I use it a lot for small stream salmon, especially silvers where you often need to move very large flies and do it with a roll cast while adding English, a reach while holding your mouth exactly right, and flicking your tongue... or something like that. Loading the rod can be very tough in a lot of these situations and being able to pick up a very short line and get it back on the water exactly where you want it is often much easier with a heavy shooting head.