Mitsubishi talks a lot about their improved iris design and action, noting in particular that it is designed to deal with scenes that change back and forth quickly. That's a huge plus, and they do have one of the smoother iris actions out there.
Their solution seems to be notably effective with one type of situation very common in movies. That would be a couple of people talking in a darker room. With the background not very bright, the iris can do its thing, but, cutting back from the shot of one person, to another (lets say one has a whitish shirt, and the other a medium blue. As those would be the brightest large objects in our scene, the iris would open more, for the scene with the blue shirt, and as the scene cuts back every few seconds, you get to see the iris open and close. With the Mits, they observe each frame, looking for fast transitions (back and forth) that are repeated, and makes adjustments to the iris action to improve it. Well done!