We lost everything but the local CBS and ABC stations (but gained a few line Antenna TV) after the switch to HD broadcasts. We live right outside DC, but at the bottom of a hill, on the opposite side from the transmitters. Before HD the reception was crappy but we could usually pick up the other stations.
ETA: I put an aerial antenna in the attic – no way I’d get on the roof – which helped, but again that was pre-HD. Doesn’t help that we’re surrounded by trees.