18 g/cc tungsten is absolutely, hands down, 100% the best shotgun payload available today. Especially, as rukiddin mentioned, in a subgauge. I shot a tundra swan in NC with a .410 loaded with TSS 7 1/2s. Roughly 40 yards straight up and he dish-ragged. The payload went through the breast, body, and out his back. I've completely quit carrying a 12 gauge for turkeys. But tungsten is expensive. I won't pay what it cost to shoot it at ducks routinely. I've have killed a few with .410 and tungsten hand loads. That's fun and I'll do it periodically. But you can make 17 .410 shells with a pound of shot. So ~ $2.75 a shell for a novelty to hunt with once or twice a year. The .410 option should let my son shoot at ducks a year or two sooner than he otherwise could. But given the cost, I don't see tungsten replacing steel shot and a 12 gauge as my everyday duck hunting choice.