Ian, I totally agree with you, I believe that for most applications in magic a half an inch brief is excellent if it has correct rhythm.
Martin Nash had a very small brief, but we are still talking about 1-2mm. He was very proficient even with a very tiny brief. I got useful tips from his videos.
Jason England is also very good at the move, but that brief seems too small for me. There is a video of Yiannis where he demonstrates a pure Walter Scott Second Deal: (http://www.youtube.com/watch?v=6IsdfXb0Aq4
It seems very very small, maybe what I am looking for.
And Jean-Jacques Sanvert:
(http://www.youtube.com/watch?v=9QogtLNt ... apOChZM%3D
) minute 2:00, where he has the Tally Ho Circle Back Blue.
I am still not fully convinced about the truth about real cheats using it, because I don't think it will be 100% reliable, but it came from one of them...