Just wanted to report in that lately I have also noticed a sharp drop in the quality of HD channels. I first noticed IFC in HD looked WORESE than its SD counterpart. Travel Channel HD was also looking pretty bad. Its gotten slightly better but come on, I know when someone is cranking up the compression ratio.
People from all over the country are reporting the same issues at the same time yet somehow its the fault of OUR equipment. It started around last week when an update was pushed and my box rebooted itself.