We have spent the past two days looking at David Harris' status. What kind of free agent he will be is yet to be determined. It depends on the CBA. Using the past year's rules, he would be a restricted free agent. The Jets could tender (or franchise) him and let him walk if another team wants to give up picks and a huge deal. They could lock him up for a long time. They could just let him walk.
To me, there is no decision. Harris is an elite player. The 3-4 defense is a system built around linebacker play. They make the plays as the big linemen eat up blockers. There is no replacement evident who could do close to the job he does. I vote lock Harris up for a long time. In fact, I think this should be the top priority for the Jets before the wide receivers, other free agents they have, free agents from other teams, and the Draft (assuming a lockout doesn't make that happen before free agency.