I've owned one, best friend just got one (ah8046) he got the 7+1 version. More parts and barrels for the 5+1, but for a dedicated HD shotty the 7+1 is awesome. (there is a 28" for the 7+1 but that and the 20" I believe are the only options)
Couple differences some parts are made in Mexico. Pricewise less machining on the receiver lowers costs as well due to the safety not on it.
Trigger gaurd is plastic, it can break, but I'm the only person thats had that happen and they do replace it for free no need to send the gun in, just the trigger gaurd in an envelope. Maybe I got a bad one? But great service fixing it for me.
FYI it might come with wood dowel for hunting remove barrel, tilt down dowel falls out, put back together and its 5+1 shells. 1 more than the stock remington.
Can handle buckshot IMO better than the remington.
Great shotgun 80% the upgrades of a remington are available (all the same products just a few less companies for certain parts)
Can put on a sidesaddle, but be careful due to the thinner receiver you can warp it by installing a screw the ONLY downside. they have a cheaper production process due to looser tolerances so they don't seem to have factory issues like remington from cost cutting. (remington had to meet their price to be competitive, mossberg they didn't have to change a thing)
Beads replaceable, in the short term it will work for HD but you would prefer a 18.5" barrel (I love me a vent rib barrel but I'm apparently unusual) It might be cheaper to get the short barrel and later find a longer barrel due to demand than the other way around.
I love them, and the shell lifter stays up so if you have gloves on less chance to catch a finger while loading... I did it on the 870 I have a few times, once in stress could be lethal.
P.S. next time this goes in the other gun forum. but were more than happy to answer you regardless.