i can't speak to the the "tactical" side of things, but I almost bought an 870 express 28". I was bothered that the top of the vented rib wasnt straight - it had a wave to it that I really noticed when sighting down the barrel. And this wasn't a one-off defect. I tried three different 870 expresses (including trying out my buddies) and they all had the wobble down the rib.
In the end, i spent more money (almost double, actually) and went with non-tactical Benelli Supernova. No regrets, and money well spent IMO. The Benelli is very well built, and shoots even better. The Comfortech stock and the fact that the Benelli will chamber anything in 12ga from 2 3/4 through 3 1/2 is a bonus. Teardown and cleaning is simple as well, and no tools required.