It is interesting reading about how much better the ST30 PQ gets using HDMI photo and mid panel settings. If you used a good calibration disc, you might be surprised how far off your are. I have a theory that the after August builds, having taken care of the FBr problem (at a minimum) has produced a ST30 that exhibits different traits then the earlier builds. Here is my experience with my October build 42ST30.
I used D-Nice break-in and final calibration guidelines. What I noticed was very black blacks lacking detail and overly saturated colors, producing a very dark picture, what I might expect in a FBr fix. If you go back, a lot of people on here were reporting they thought their PQ got better after their A-board was replaced, blacks were blacker, colors deeper. Some had already started to back off the D-Nice color settings, going down into the 30's. The PQ was not so much dim as it was dark. Thus, people started to look for better settings to lighten things up and found their way to the normal color, HDMI Photo and Mid-Panel settings. I tried those settings as well and they looked OK, but lacking. One problem is, I have a VT25 to compare with. That VT was calibrated by D-Nice and I learned to trust his work and dedication to finding the most correct settings for the very best PQ that can be pumped out of a TV. I finally broke out my trusty Sound & Vision's Avia Calibration DVD I used on my Pioneer Elite Pro.
I started by keeping the D-Nice WB cuts exactly the same. I also kept the 2.2 Gamma, Low Panel and Warm Color 2 settings because I knew the most accurate colors and Gamma was going to come from there. Working with Contrast first, Avia had me reaching into the high 80's to obtain the optimum setting. Next, I had to increase Brightness into the mid 60's to obtain the optimum black, gray and shadow detail. Going back to Contrast, I was able to back down the setting to low 80's. Going back to Brightness, I could lower the setting to 63. Checking Color Saturation, it was dead-on at 45 (D-Nice's setting) and Tint/Hue was accurate at "0" setting. The TV was slightly under emphasizing Reds and Greens, almost spot on, excellent for a processor in this price range. When I was done, I had a PQ that blows away the HDMI Photo and Mid-Panel gyrations. The colors are vibrant but natural, and I know correct. The blacks are pure black when they are supposed to be and the shadow detail is excellent. The clincher is the panel is plenty bright enough now.
I really think something has changed from the earlier builds to those built after August, or had the A boards changed. That's why I've asked D-Nice about it. In the end, to each his own on what looks good to their own eyes but I promise you, the HDMI Photo trick is not giving you the best your TV can be.