Sogood51 - you missed the point entirely. You should read the WHOLE white-paper:
http://www.positive-feedback.com/Issue14/spdif.htm
There are "sweet-spots" in length for S/PDIF because of the way transports are made. I sell 1m cables to customers that have my modded Transports. This enables them to use the shorter cable. Extremely short, such as 9 inches is also a "sweet-spot". Stock Transports can sound better with the 1.5m cable, depending on the cable and the Transport. Most of them do, but there are exceptions. If the cable is not 75 ohms or is very lossy, then it may sound the same in all lengths....
Steve N.
Empirical Audio
Manufacturer