I have one on my tactical (cough, cough) Winchester Defender. I bought it because I couldn't figure a cheap way to add ghost ring sights. I use the sights but they are mounted a little low for me - I just make do. It is handy when speed reloading during a 3 gun match. Just flip the gun upside down and hold onto the head shield.
Cheep but I figured it is better than spending more on ghost ring sights than the shotgun is worth.