When Winchester undertook to reduce the cost of manufacturing their repeaters, they did it by utilizing the cheapest internals they could find, and they introduced the 1200/1400 series. They were fraught with problems and many internal parts failures right from the get go, and they helped the slide of once proud Winchester Corporation into eventual sell out. They dropped the 1400 and the 1200 morphed into the 1300, then the speed pump, now the SXP.
Mossberg and Remington have been basically unchanged for 50+ years. The Benelli Nova likewise remains constant, and we all know how Benelli likes "new and improved". Manufacturers do not change pump guns other than to address issues, or add new models of the same base gun with different options.
I do realize there are a lot of guys who have these guns and like them, but that doesn't change the facts. If I didn't already have one, I wouldn't buy one.