The kitchen sink must not be too hard on it, after all it hits the main stack eventually :P I've seen a lot of NY state cast iron cast at the Monitor Iron Works

The kitchen sink must not be too hard on it, after all it hits the main stack eventually :P I've seen a lot of NY state cast iron cast at the Monitor Iron Works, like Monitor and Merrimack, the US Civil War era ironclad warships. Still in service, still not leaking. Now of course that's survivor bias! You usually don't need expansion joints on cast iron...not that most residential construction gets them even when they are needed. It's detectable in an X-ray, unlike PVC, though I doubt that's of interest to 99% of DWV applications! No-hub is easier to adjust and rework than glued plastic pipe, as you can always loosen the coupling. Hub-and-spigot with rubber gaskets is effectively permanent, you have to seat it with lube and a mechanical assist puller usually. On the old lead and oakum joints, you can always dig out the lead to change orientation (not fun), or caulk it (as in with irons) more if there's seepage on a line.