From my experience the Mossberg and Rem 870 have a lot of similarities. Both are reliable and built like tanks. Steel receivers on all I've seen and strong, smooth twin action bars. Quality and dependabliity is not an issue with either and cost no object between the two I'd spring for a Wingmaster myself. However aside from being cheaper I think the Mossberg has a few design advantages.
1. On the Mossberg there's no trapdoor or whatever you call it to bite your thumb if you have to load shells in a hurry, a big plus in my book.
2. Many Mossbergs are available with factory porting, to my knowledge they are the only shotgun company to offer this.
3. The safety on a Mossberg is thumb activated, on top of the receiver (like a Browning BPS) and therefore ambidexterous. On the Remington it is on the trigger guard.
4. The "action button" or whatever you call the thing the unlocks the slide is on the left side and back of the trigger guard on the Mossberg, hold it with the thumb if you are right handed. To me this is more comfortable than the front of the trigger guard on the right placement of the Benelli, Ithaca, and (I believe Remington).
5. If I am not mistaken with the plug out a Mossberg holds 6 2 3/4 shells and the Remington holds 5, but I haven't looked at an 870 in quite a while so don't hold me to this one.
Don't know if it's been mentioned but go to some gun shops and check out the Ithaca 37 Featherlight, Remington, Browning BPS, Mossberg, and Benelli Nova and Supernova, I don't think you can go wrong with any of these pump guns. The only "good" pumps I've seen I didn't like were the Winchesters, to me they just looked and felt cheaper than the others but that's all subjective.
