DAVE ABRAMS rules!
Sorry, I couldn't resist -- you already know this. Dave came to my home yesterday to calibrate my 7178. He did a fantastic job, and Dave is an incredible wealth of information. For instance, I had my Denon AVR4306 and PS3 set to component color space (Ycbr blah blah), and he advised there would be less error in the color conversion if I kept it in the RGB space right down the line, so that's what we did.
I was afraid that, after the calibration, my set wouldn't be as bright. On the contrary... post-calibration the set is twice as bright as before, with much more accurate and deeper black levels. This gives the picture an immersive dose of reality. My partner came upstairs after Dave left and commented, "Wow, the picture looks so natural now". I couldn't agree more.
Initially I felt that skin tones were a bit on the red side, but after watching it for a while I felt they were far more accurate than the yellow-ish tones I had been accustomed to. Watching HDTV material such as Grey's Anatomy, which I feel is one of the best broadcast HD programs in terms of picture quality, appeared less saturated than pre-calibration and far more pleasing. Before the calibration, everyone had the same skin tone. Post-calibration, you could actually see the differences between the skin tones of the different actors.
Regarding my color dithering issue, posted previously, Dave pointed out that most source material utilizes a 24-bit color space (8 bits each for R, G, and B). This allows a color palette of 16.7 million colors -- similar to what we all use on our PCs and Macs -- but at a 71" screen size could result in banding in continuous tone areas. Combine that with additional video/color compression on satellite, DVD, and Blu-ray source material, and it quickly becomes clear why we see color banding in some situations. I believe Blu-ray mitigates this somewhat with additional noise in the video signal, making it more film-like and breaking up color transitions. The only real fix to this issue would be source material encoded in 10-bit or higher color combined with HDMI 1.3 transport. HDMI 1.3 allows for 30-bit to 48-bit color, or a shift from HDMI 1.2's millions of colors to billions on HDMI 1.3's low end to trillions on the high end. Until the video sources take advantage of more than 24-bit color, which is unlikely for a long while, the only advantage to HDMI 1.3's expanded color gamut will most likely be for computer gaming.
I am thrilled with my calibration, and highly recommend Dave to anyone who wants to get every ounce of performance from their set. A few months ago I tried doing my own calibration with a Gretag Macbeth EyeOne colorimeter and software... well, Dave puts that whole process to shame.