It really depends on the staff that is enforcing the line.
There is another thread on the same topic:
http://www.flyertalk.com/forum/star-...-security.html
From my experience at LHR, ARN, NRT, and EWR the line is definitely shorter. ARN had no line compared to 100+ in the regular line, LHR had 5 people but I couldn't see the other line as it was partitioned off. Unlike ARN and LHR where it was a separate line and separate machines, NRT and EWR fed into the same line as the regular line so it was just a shortcut.