Good to 'see you' on the UK forum as well. On all of the SIM2 projectors I have seen, the dithering in the black has been virtually invisible from about 6ft away. Even the 'contentious Wiggles' from the AVSForum found the dither particularly minimal on the SIMS. For those on the form not familiar with the artifact we are discussing, get a DLP projector to project 'black' and then go up to the screen and you will see a kind of greeny black revolving movement of the mirrors. This is what I understand as dither in the dark areas. It can be made worse by overdriving the contrast as well. It is this artifact that the extra green segment in the colour wheel diminishes.
I believe SIM2 have researched this problem thoroughly and have found that the suppression of the dither on their pj's is minimal. However, the resulting light reduction caused by having an extra green segment in the light path is highly significant. Hence, I suspect they will not go with the 7 segment colour wheel. Frankly, I think this is a tribute to their thoroughness and dedication to producing image quality excellence. Hope this helps.