An emphasis on signal source as affecting the advisability of buying HDTV is in order. HDTV over the air signals are prone to break up and become unuseable when the same antennna and the same channel is fine with an analog (regular) signal. This can be caused by rain/snow, upper air storm, or even wind blowing trees near the antenna.

Satelite HDTV signals are available for only 10-15% of the channels and none of the local TV channels yet.

I had to spend $1500 on antennas, rotors, dishes and wiring. No that didn't include converter boxes or TVs. And I get excellent reception only about 50% of the time. Yes I've had the antenna people out repeatedly.

If you live in an area with beautiful sight lines to transmission towers or a cable system that provides a high number of Hi-Def channels, it is a different story.

But if there is any doubt, get the antenna installers out to measure your signals and get an antenna quote before buying.