I went to check it out, here's a link. http://www.mossberg.com/category/series/590-shockwave/
As I suspected it's a 14'' barrel. Might be right handy. I'd love to play with one to see if Alfonse has hit on something.
I agree I didn't like the pistol grip but maybe this is the ticket for a short handle and being shorter overall, maybe it would be manageable with one hand moving around. Not shooting but freeing up the weak hand for other stuff.