Agreed - AV9000s with a nice razor sharp tube have a spectacular picture. I have seen a few type 43XX's where the picture has gone a bit soft, and they're disappointing. I think the great picture has a lot to do with the multiple layers of antireflective coatings, and the contrast screen.
Just out of interest, a small ray of sunlight was hitting the sensor on top of my AV9000, and by turning the set (from a normal viewing distance) so the sun was on and then off the light sensor you could clearly see the automatic contrast function of the TV working. It's something that you take a bit for granted with a B&O TV, but the difference in the picture is obvious.
How about a workbench project where we replace the Prologic for digital surround? That would be a fun one to do!