I've been using Nordic Components parts since they started making extensions. I've ever had any issues. On top of that, the folks working at Nordic are always great to deal with.
Aimpoint for a Red Dot. If you're looking for magnification, the NightForce NXS compact series has proven to be a good choice. I've been using a 1-4 on my 3 gun rifle for about four years, and have had zero issues. I've been able to reliably and consistently hit targets from point blank to 600 yards.
The Vortex scopes have a good reputation as well, I just have not been able to play with one personally.
Personal preference. Some folks don't like cheap plastic parts on massively expensive guns. That's why you see a lot of new Kimber owners replacing their mainspring housing.
Regardless of whether he baits deer, he is still a high profile celebrity type that speaks out FOR our rights. We need more of that, and less of the sissies that try and tell us we're all evil because we're gun owners.
Benelli's are inertia driven. Adding a bunch of weight to the shotgun affects the reliability of the system. The XRail is not light to begin with, and then you stuff it full of shells on top of that. I don't see them being a great choice on the Benelli's.
I shot with the owner of RCI at the Adams Arms Ozark 3 gun last month. It seemed to work like a champ on his Mossberg and his buddy's 1100.
As GTPSC said, a lot will depend on the ammo itself. My M1's work great with Briley LightMod or IC and Remington 8 pellet, Federal 8 or 9 pellet, or Hornady TAP. Neither tube seems to like the Remington 9 pellet I've got very much.