I have the 12.5 ghost ring model. I changed the choke to full for bunny hunting this year. I netted several with it. I have used it on clays and had a pile of fun with it. Its compact, and great in thick bush for quick maneuvering. I think it's a great little shotgun. 870 parts do fit on it, the choke was a Remington 870 screwed in just fine.
The downsides are - sites - took some getting used too - came from the factory REALLY low. at 20 yards it was several inches below where I aimed. That was easy enough to fix, raise the rear site all the way and put the top of the front site about 3/4 up the ring. I didn't miss after that if I followed that siting. It's heavy. I mean HEAVY, for such a little gun. But that don't bug me much.
You need to take it down and clean it up really well, polish the action down (mine had a burr) and give it a good go over. After that, it's as reliable as can be. It's no custom $2000 hand built gun. But it cycles smoothly enough and makes a great bush gun.
You would think with a 12.5 barrel that it would be not so good for clays, but, yes, with a change in the choke, it was a clay destroyer. Surprised ALL of us actually! I've seen videos where they change out the furniture on one to 870 tactical stuff, looks great with an adjustable tac stock!