My six year old grandson carrys it on his back on one of our "adventure" walks. I yell to him, "bend over Derrick". I wipe out all of our enemies on the back of my best friend and grandson. He digs it. I am still his hero.
To each his own. I wouldn't waste my time building it or my money buying it, but it would probably be fun to go out and shoot at random. I wouldn't use it to save my family. Unless it was the only thing I had.
looks like one under the shooters left hand side barrel. however it looks to me like the vert grip is on the right hand barrel, likely would be placing your arm in front of the nade if you were using the vert grip. could sting.