I have a Stoeger m2000. I've never held a Benneli.
I can tell you my experience with the Stoeger, though.
Unless things have changed, it is only made with a 5 shot capacity. The only place I could find a magazine extension was a guy in TX who machines them from aircraft aluminum, around $80, mine works flawlessly and an easy install if you have a dremel type tool or small files.
The Stoeger inertia action is supposed to be the same as the Benelli. It needs to have a stout shell to make the action rack properly. I don't have mine nearly broken in yet and sometimes it will not cyle with game load shells.
I had some cheap shells I was using when I took it to a defensive shotgun class and that was not the place to learn. It did cycle Winchester bulk pack 12 gauge shells, though.
It shoots reduced recoil Winchester slugs and buckshot without a problem and dead on the aim point using the bead sight. When patterning the gun I put the second 1 oz. slug into the hole made from my first shot, it made the instructor do a double take to make sure I didn't miss the target at 40 yards.
The bolt release button on the side of the receiver is not as easy to operate as I would like, taking more force than I can generate repeatedly while holding the shotgun in firing position. Hopefully this will get better with use, it has only had a few hundred rounds through it.
I'm happy with mine, ymmv.