I have 2 HD sets, a 57 inch Sony and 55 inch Mitsubishi. I have seen some pixelation a few times on some of the HD channels, which I understand they are fine tuning, but not a drastic reduction in PQ.
FWIW, it's ok to complain about PQ, the squeaky wheel gets the grease. I have no issues with OTA HD, if I do, I email our local engineers and they are right on it. Our local ABC had some issues for about a month and they finally found the culprit but the station engineer really apprieciated our feedback. I wish we could get some Voom engineer involvement on this board.