I own one. It's a 10" 12 gauge AOW with a tax stamp.
I wanted it really really bad, had it built to spec - it's a ringer for the one Mel Gibson carried in "Mad Max", and when the papers came back and I got it to the range... it wasn't what I was hoping for.
The main problem is that shotgun shells aren't loaded to work in a 10" barrel, and the short barrels magnify differences between shells. What you'd consider an "ordinary" shell would give a beachball-sized fireball (fun!) and enough recoil for the trigger guard or forward trigger to cut my index finger. (ouch!) My first firearm was a .44 Magnum; I still view that amount of recoil as "normal for a pistol." The boomer has as much more recoil than the .44 as the .44 does over, say, a .32. Plus the sloping grip makes it hard to hold on to; it sldes back in my hand, exaggerating the "cuts from the trigger guard" problem. It is serious No Fun to shoot.
I eventually found some shells marked "rabbit load" that had much less recoil, down below .44 even. But with the short barrels, the shot would bounce off a cardboard box at fifteen feet and lay on the ground in front of it. Not stretching the truth any there.
It's a safe queen now; I haven't shot it in years.
Now, from the vantage of time to think about it, for someone who was set up to load their own shotgun shells (I'm not, and don't plan to) the ammo problem could be probably be solved by handloading.
A conventional pistol grip instead of the "flintlock style" cut-down shotgun grip would be a better fix, but the receiver used on mine has long tangs for the shotgun wrist, the stub of which forms the grip. I considered cutting the tangs off and making a better grip, but there's just air back there then; a proper job would involve welding some metal in there to anchor the grip to. Several local welders judged that the frame is a casting, and in their opinion the welds would eventually crack given the recoil load involved.
I'm not trying to talk you out of it, but unless you set up to load your own shells, you might not want to shoot it much. You might not even care about shooting it; it's certainly an attention-getter just laying there on the bench, but it would be nice to be able to toss some shot downrange without the obligatory blood sacrifice.