I am big fan of Jeff Hunsberger's posts about the way he uses OmniFocus. Jeff and I share in common that we have line management roles in larger organisations that offer their own set of complexities. Vanilla GTD® and classical project management alone seem to leave a gap in your managerial responsibilities which Jeff captures and addresses nicely in this post.
Projects obviously have their place but because GTD isn't a project management methodology and because I'm not a project manager in the strictest sense they take a backseat to Contexts when it comes to actually working on things. Projects still are necessary for me, however, so don't think that I threw the baby out with the bathwater. It is just that I think about them differently than in the typical GTD sense.
It is also worthwhile reading Jeff's entire OmniFocus post series again. Great work and very valuable.