John,
My SBE2 has one season on it. Not one malfunction,no jambs, nothing. It has never had anything except 3" and 3 1/2" shells through it. It probably saw 20 plus days of salt last season, some were NASTY. Like you, I use my stuff hard. I hunt alone a lot and put out a lot of gear. I can't baby any of my equipment. I spray it down with something to displace water (not oil) such as "barricade","sheath", "corrosion X" or any other water displacing spray. Oil collects dirt and grime. I should say I HOSE it down after saltwater use, spray it until it runs out everywhere. After a 2-3 day trip I will strip it down and rinse and wipe all parts. Just last week I completely stripped my SBE2 and Win Super X2 down for cleaning and summer storage. The SX2 saw several years of hard use before I got the SBE2. Comparing them side by side, no comparison at all. The inertia system of the Benelli is so much simpler and easier to clean, and stays cleaner.
The dealer I got the SBE2 from said the upgrades from the 1-2 really helped with the saltwater issues they had with the 1's. As far as I can tell there are NO bare carbon steel parts on the SBE2, including springs. The recoil spring in the stock was an issue on the originals. Water would get in and rust the bare spring. The only issue I've had with mine has been surface rust on the barrel. I have the black finish. I now keep it well covered with protectant and there hasn't been an issue. I can't find any evidence of the original surface rust that I saw at this point.
For an auto loader, the SBE2 is rather easy to swap ammo in and out of in a boat. No need to point it up, down, sideways... to make the first shell feed into the chamber. But you must let the bolt slam home or it will not fire if the bolt isn't completely locked in. Hunting with divers/puddlers/brant/geese all possible in the same location there are days I swap ammo in/out as birds are working. I think the SBE2 makes this as easy as it can be with a semi. One of the reasons I had looked at O/U such as you are asking about. The convenience of unloading and loading is a big safety issue.
One final thing, a quality O/U is a thing of beauty. An SBE2 is a tool just like a moss 500 or rem 870 (no offense meant!). That said, I'll be using the SBE2 for a long time to come. Many days, especially in salt, I'd just as soon have a good tool.
Gene