GLH,
Actually you will end up using both optical and analog. In general terms for DVD movies you will want to use the optical connector and let the receivers decoders process the signal. DVD audio however will not output via the optical as they are encoded for analog output. So to play a DVD audio you will need to use the analog output from the DVD player to the analog inputs of the receiver.
There are exceptions to this, but it depends on your DVD player and your receiver. If your receiver does not let you switch between Digital and ext. inputs easily for the same source, and if your DVD player has built in decoders for THX and DTS then you may opt to use the DVD players built in decoder and bass management and go only with the Analog outputs.
