You will get better audio and video quality with the composite A/V cables. Note that the 'channel 3' RF output from many of the converter boxes have mono sound, not stereo. So if stereo sound is important, use the A/V connections.

Most TVs made before 1990 or so do not have A/V inputs - just antenna inputs. (I bought one of the very first TVs to sport A/V connections, a Sony Profeel system, in about 1982. Other manufacturers followed suit shortly afterward.) The RF coaxial outputs are provided to support the older gear.

You certainly can use both sets of outputs from your converter box.

i prefer to use the composites if both have it.

if the tv does not support it i use composite to teh VCR, tehn coax from it. if you MUST use coax for both, use chan 3 out of teh converter and ch4 out of the VCR to the TV. i've seen too many times where setting both to ch3 or both to ch4 causes degraded picture.

Thanks wws and davidandkasie.