Nothing so awesomely "grainy" as over-compressed HD. And in my market, OTA HD looks like dog crap. It is like they degrade or over compress it on purpose so that you buy through the MSO or DBS provider (where they get paid for re-transmission).
OTA HD looks good as long as there isn't any sub channels, but almost every channel has at least one sub now, there are only a handful that don't.--In need of a Vegas vacation.
In LA CBS and Fox HD OTA look pretty bad.
Grainy? That's the exact opposite of over-compressed HD. Over-compressed HD has no grain. Grain preservation requires a high bitrate.
Fox looks bad in every market because it is only 720p.This is why ABC also looks like shit.
By "grainy" in quotes I meant compression artifacts.
Fox looks bad in LA because OTA has bad compression artifacts, not because it is 720P. It is like they make it look bad on purpose. Sports programming looks particularly bad.