I'll third the motion on using line rule. I picked up the use of it from Jay's forum posts, thinking that it sounded like a good concept. I would absolutely never go back to edge rule.

Line rule gives you totally accurate layout information, it's just so easy to be right on. Sometimes I have laid out a beam using square rule because it doesn't have much joinery, but it kind of feels like walking onto the jobsite without pants on or something! Just kind on naked...
The other day I snapped lines on a beam that I just needed to accurately plane with my big Makita. The ends were perfectly plumb/ level to one another with no guesswork.