I set it back up again and found that an extra panel showed up in the OS X display preferences, and this had Overscan setting checked. I unchecked this setting and now the image perfectly fills the display (well almost - I can use FILL mode on the TV to stretch it out just a little). For the most part the display looks crisp, but some things are washed out no matter what I do. In general, however, the text looks very readable. I will have to play with it some more to see how I like it.
One thing that I haven't figured out is the audio. I don't plan on using the tv speakers when displaying computer video, I should be able to if I want to do so. However, with no audio connected or with the computer's audio connected, I only get a loud hum that disappears when I set the backlight to full. Does anybody have experience with this model to tell me what I am doing wrong? The tv has a set of audio rca connectors next to the hdmi connectors that is labelled hdmi-dvi. I don't know if there is something that has to be done to enable these inputs.