If we were to end this season in the exact position draft-wise we are in right now (10th), the consensus pick falling to us is Michael Oher. If you don't know who he is, take a moment and look that up. Suffice to say that I seriously doubt that Jared Allen would be looking forward to that match-up.
I am of the strong opinion that all things being equal, you are far better off delving into FA for defensive linemen and defensive backs (especially in man coverage) and looking early in the draft (we don't do this, historically, btw) for offensive linemen. Quicker impact, imo. Justin the bustin Harrell, for example, has been declared by all as a HUGE reach pick at 16. He finished in the draft prognistication boards (consensus) at 31. 31st pick in the draft for an injured player. The "HUGE REACH" was nothing of the kind, at the time. (FYI, Hawk was exactly where we took him---5th) DT's and DE's are MUCH less likely to come out of the draft and play difference-making football early on.
DRAFT O linemen....FA certain defensive position players... My opinion.