Very articulated. Came with the umbilical plug and cord, as well as a pellet rifle. It also has parts to build the gamma version as seen in Rebuild 3.0.
But if you've handled HG Gundam before, then it feels the same handling the Koto; it is a model kit as opposed to the SOC being an actual action figure with diecast content.
I might end up getting the other Koto kits though seeing that the SOC Spec line is somewhat dead.