My 2016 LR4 did not come equipped with the HD package, and at the time of purchase I didn't think it would be a problem. I've been in some pretty sticky situations and Terrain Response has always figured it out (so far), but as I get comfortable with the vehicle I'm pushing it harder and harder. After looking at quite a few upgrades, I'm starting to hesitate a bit due to the elephant in the room: I don't have a center or rear locking differential. Depending on who you talk to, this is either not "that" big of a deal, or it's a massive draw-back that prevents it from being a good off-roader. Obviously I think it depends on what you're doing, and in my personal experience I used the rear-locker on my old Jeep Cherokee quite a bit. I'm starting to think not having the HD package is going to prevent me from facing the more difficult off-road challenges. Here's the thing: I don't know how much better off the LR4 is with the HD package. As I said the Terrain Response is pretty damn good, but how much better is the rig with the rear/center locker and hi/lo ranges? This might be hard to quantify, but I'm hoping members of this community can clue me in. If it's substantial, I'm considering a swap between my LR4 and an LR4 with the HD package (equivalent miles). I've never done anything like that before and it seems like a massive pain in the ass (not counting the potential for substantial added cost).