The RS15 seems about comparable to the Mitsubishi as well, but it does not use a dynamic iris. That would indicate that in an even darker (dark) scene (such as the Bond night train), the iris will get the Mitsubishi a touch blacker than this JVC, although the RS25/RS35/RS50/RS60 will still have the advantage.
Finally, a little side by side imagery. On the left is the HC9000D, on the right the JVC HD250.
Note there are two images. I mentioned elsewhere that the HC9000 (on the left) iris is a slow one.
The first image was taken immediately after putting up a black screen, and pausing. The image immediately below it let a black frame run for a several seconds before taking the picture. The first one indicates roughly what the dynamic iris will do on the Mitsubishi, rather quickly. However, if the dark scene is very long, the blacks will continue to drop it seems, until you get the second image.