If the coax antenna output of the tuner delivers several channels at once where your TV channel selector is used to pick one, the antenna output may be useful. Otherwise avoid using it.
For channels that were analog to begin with, the composite output may give a better picture than the S-video output, it depends on how good the comb filter in the tuner box is. You may wish to run both composite and S-video cables between tuner and TV.
Other video hints: http://members.aol.com/ajaynejr/video.htm
The 4700 only has RF coaxial and composite outputs. I'm receiving a new Denon 3802 tomorrow so I will be able to quickly A/B test the outputs and should be able to tell which one is better. The TV is old (soon to be replaced) and does not have S-video inputs.