David Allen has an excellent series of posts on this passage (HT: David Alan Black), which I think is the key to the entire book. I am, of course, especially impressed with the fact that much of what he says is compatible with the way I believe the passage should be interpreted!
Agree or disagree, I think one must admit this is exceptionally well written and reasoned.
I will doubtless acquire a copy of his commentary on Hebrews in the New American Commentary Series [Hebrews: 35 (New American Commentary)