My preference is the Mossberg over the Remington, because, due to my location, the gun must be shipped to a gunsmith for attention, and Mossberg parts are neither held in place by stab-locks or rivets, so are easy to replace ith little more than a screwdriver should a part fail. My gun is the 590, but a 500 with a short barrel is lighter, although the solid magazine tube end makes cleaning the magazine tube more challenging. That said, I'm not a fan of the Maverick 88. The stock is light and flimsy, and doesn't handle recoil very well. The actions of the ones I've handled are gritty and need much work with valve grinding compound to smooth out and slick up, and I prefer the tang mounted safety to a cross bolt.
Another consideration is the choice of a semi-auto shotgun. The advantages over the pump, is that in a stress situation the gun won't short stroke, the solid front end feels more stable, and provides a better platform should you need to shoot from a supported slung up position, than a magazine or barrel mounted sling attachment which is typical of most pump guns.
There is very little advantage to a long magazine on a bear guns, even though many bear guns seem to be equipped ith them. I upgraded to the a Magpul SGA stock from the Speedfeed for the adjustable LOP, and the improvement in gun handling and recoil control is remarkable, although I'm not crazy about the look. I epoxied a course thread swivel stud to the underside of the stock for convenience. Because the rocks along the coast are slippery, I got a heat shield to help protect the barrel from dents if I take a fall. When it comes to barrel lengths, I don't recommend a barrel length any shorter than 14", in fact I don't want a barrel so short that I can get my support hand out on front of the muzzle with the gun held in my shoulder. If, on a cold wet day, in the heat of the moment, you energetically cycle the action, and your hand slips past the slide just as you press the trigger, and the gun fires while your hand in front of the muzzle, its a game changer. If you do choose a very short barrel, ensure the gun is fitted with a hand-stop.
Rifle sights, of the ghost ring and rectangular post variety are extremely fast and accurate. The habit of mounting the bead right on the top of barrel without an intervening pedestal, on a pump or auto shotguns leaves much to be desired, since the front sight has to be equal in height to the rear if the gun is to hit point of aim. The receiver of the pump and auto shotgun is always higher than the barrel, and a tapered barrel increases the error. If a bead front sight is mounted right on the barrel, you'll have to depress the muzzle until the bead disappears from sight, in order to hit your intended target, otherwise the gun will shoot high.
Here's an example of the type of encounters I have experienced over the years . . .

