With regard to holding the angle be warned that MANY here have been told by friends and even teaching pros that they were but video revealed they were not. Video of your swing is the best way to KNOW that you're accomplishing it.
Peter
Update:
I took a look at the Gary Edwards site. There is not a lot of information but reviewing the video of people presumably employing his swing, they are learly not tour pro swings. There is no lower body movement prior to the club beginning the downswing and this is common in all tour pros I've examined on video. This and some other comments make the swing seem to be to be close to the BGG swing or the IMA swing in Impact Backwards drill #5.
This message has been edited by sagf_moderator on May 30, 2010 10:35 AM