While technically not a newbie, I am a HDTV newbie. My cable company, Comcast, offers HDTV programming for my locals and HBO, ESPN, PBS, etc. This is what I would probably get when I get my new HDTV set. However, I have heard from a couple of sources that this is not as good a quality as I would get if I put an antenna on my roof (at least for the national networks.) This is due to the fact that cable's bandwidth is limited and the signal is compressed more than an over the air signal. Is this true? Thanks for your help.