I was playing with one yesterday at the local Class III FFL.
I just examined and operated it dry, of course, didn't shoot it. VERY compact, built on a Maverick 88 base (Mossberg's "economy" line), with a 9" barrel and that cute little folding forend handle. It holds two in the mag tube and of course one in the chamber. Operation was quite smooth, better than a standard Maverick. No sights at all, not even a bead. Probably better to shoot 12 Guage "target" or small birdshot loads, I'd bet, as I suspect it's no fun shooting with full-house loads, not even 2 3/4" "tactical" 00. Sells for about $700.
Seems like the "obvious" choice if you're inclined to use a SG for CCW or for leaving inside the automodeal in a purpose-built holster, unless of course you prefer the "Auto and Burglar Gun" (I played with that one, too), which is the 20 guage double barreled pistol SG that goes for about $900, and has a tritium front bead! It seems very well made, but again, I doubt it's much fun to actually shoot.
Both of these are AOWs of course, so there's only a $5 transfer FFA tax to pay, instead of the $200 you'd have to pay for a stocked short-barrel shotgun.
They're both really cute guns, but unless you have a specific need for something like that, they're not much of a bargain, since you can get a real, "easier to shoot well" SG with a stock and an 18" or longer barrel for MUCH less $. Still, there's something undeniably attractive about them. Best.