Have you done the update and, if so, are you satisfied? Heard both opinions. Some say if your truck runs well without not to get the update as the update has caused some mileage and drivability issues. Some say that the update worked well.
I had it done, noticed no difference in anything. Now I have to hold on to the emissions card the dealer gave me and send it in when the registration is due or it will not be renewed.
If this is the update concerning the problematic exhaust temp high sensors, then I would recommend you get it. The problem is that if one of the sensors fails and registers extreme high temp, it will give you a "stop safely now" message and quickly shut down the engine with little advance warning. Then it cannot be restarted for at least 30 minutes, with no guarantee you can drive it very far without it happening again. That happened to me (2012 F350 6.7). Had to have it towed to dealer for warranty sensor replacement. Fortunately it did not happen in the middle of a highway or intersection.
I have experienced no noticable difference in performance since the update about 6 weeks or so ago. And that includes towing the 5er.