In my book, simplicity is better.
I have an 1897 which is a great shooting, well balanced gun and a first time shooter can operate it with minimal instruction. Of course, it is somewhat of an out of date shotgun that you will probably not find in typical gun shops.
I am not particularly fond of Benelli shotguns because they are slightly more complex to operate (so I've heard). Plus I like to stick with American gun companies. If I were to purchase a new shotgun I would probably go with the Mossberg 590. My father has one and swears by it. I have shot it in many different configurations and it always performs well. I have not personally shot a Remington 870, so I really have no frame of reference for that gun, but I am sure they are just as reliable.
I would never buy a semi-auto shotgun due to not being able to cycle through to different rounds in the mag tube. Say you have you have two door breaching rounds then slug, 00buck, slug, 00buck... you get it, you can't cycle the second breaching round if the first does the job to get to the slug. You generally have to fire the second breaching round to get to the slug without complications (IE ejecting ALL cartridges accidentally) You can with a pump gun.
All in all, I would bet my life on my 1897 since I have it regularly checked and tuned by one of the best gunsmiths in the area (in my personal opinion) that can work on the beast. It hasn't failed me yet. Plus I run around two boxes of bird load every week or two to keep proficient. I use bird load for home protection due to the lack of over penetration. I don't want to accidentally shoot a slug or buckshot through my exterior house walls, possibly hitting someone outside.