I fired one yesterday.
Let me tell you, they do not exaggerate the power of that thing. I had been firing my dad's Beretta M9A1 so I was prepared for a 9mm recoil. When I fired it, my hand flew behind my head and I staggered back several steps. The next couple of shots were better, but I still could barely control the recoil. I was able to hit a 1 foot target at 10 yards, despite almost falling over.
I love how all movies and video games have people firing those 1 handed.