The CD is a very simple design and not much can wrong with it. The ejector is very thick steel and it would be unlikely that it would break. The extractor is machined steel and it's very similar in design to the 870 extractor. The CD pump shotgun design is similar to the 870 but no parts will interchange.
I am working a review of the CD tactical pump and here are a few preview pictures.
This picture shows the two internal parts of the CD Pump, The steel bolt looks similar to the 870. The bolt sits on the charging assembly and it fits into a plastic slot on the forend. The CD pump has two shell latches like the 870 but they are shorter & much thicker and held in place by a steel pin. They aren't staked in place like the 870.
This picture shows the CD shotgun's very thick aluminum receiver. The rail is held on by five screws and the rear GRS is held on by two screws. It's a very strong rail and GRS setup. The GRS are nice and very similar to the LPA GRS.
The front Ghost ring sight which is very low profile because the rear sight is mounted on the receiver and not high up on rail.
Like I said not much can go wrong with one and all parts a drop in fit. If I had a choice between a standard Mossberg 500 or a CD pump would choose the CD pump hands down.
GC