My parents are depending upon me to help them switch to DTV in February 2009. (I'm sure many of ye also have people who need your help.) Since my parents use nothing more than rabbit ears + UHF loop, I need to get the most-sensitive box possible in order to pickup weak signals. Right now I'm torn between the Zenith DTT900 and Channel Master CM7000.
Based upon my own tests, it's a bit of a tossup. Both have excellent tuners that surpass the other tuners I have tested (Hisense, DTVpal, Zinwell), but they do not act identically. The Zenith senses at least one channel (PBS33) the CM does not. However the CM handles noise better on weak channels (WGAL8), reconstructing a viewable image while the Zenith freezes for one-two seconds (very frustrating). So the Zenith can get an extra channel, but the CM has better noise-handling and watchability.
One advantage of the Zenith is the better tuning bar that shows a "bad" signal is present, while the CM shows no signal whatsoever (0%). The Zenith's indication of a weak signal helps the viewer adjust the antenna.
For those who have BOTH boxes, what kind of results did you get for your channels?