I have reloaded and shot all that you mention. My preference is Ecotungsten or Nice Shot hands down. It is very close to lead and as a result you can use standard lead reloading recipes. Caution: pressures will be slightly higher because it is a little harder than lead, but safe to use in classic doubles.
The simple, yet highly scientific, "pliers test" shows that when squeezed Bismuth will crumble, ITX shot will crumble, while lead and Nice Shot will deform as a unit, spreading out like a bullet. 5s kills medium and small ducks real well, 4s for big ducks.
Hope this helps
