My experience with the Remington Express shotguns has been good and bad,
good in the sense that my early model ( circa late eighties or early nineties)
Express had no issues of any kind other than it did not pull up to my shoulder
as much as I liked. It didn't feel right for me and my frame size.
My Bro. in laws gun was a rust bucket. That's another story.
I have no experience with the Benelli other than it rattled worse than a
goose loose Mossberg and that turned me off when I shouldered one at a store.
It 's a matter of preference and I would find out what fits me and how it
balances for carry purposes afield if that is your intent of use.
IMHO a 3' gun is as good as a 3.5 inch gun and a 2 and 3/4 is no less effective.
The only gun I would consider in 3.5' would be a Mossberg 835 with a 24" barrel ,camo'd, with Hi-viz sights.
It's a proven gun in the 3.5 inch category, even though it does rattle a little.
I haven't heard enough good about the Remington Supermag to get a warm fuzzy about parting with my hard earned cash to buy one.
I have not been impressed with Remington with any of their new shotguns as now they seemed to have been slipping in quality.
If you can stand the rattle of the Benelli slide, I'd say Benelli.
If 3.5 ain't real nescessary, and the Benelli doesn't make your socks roll up and down, a used Wingmaster would more that suffice for an all around gun.
My humble opinion of course!