Zookie, I've done quite a bit of 4 wheelin, in jeeps,scouts,and been around several broncos. We all ended up with lockers in our machines for the extra traction, but I will tell you from my experience, there are times when you need to be able to unlock and lock at will. Prfeferably, from inside the cab. Now sure you can get out and unlock one hub if you need to, but its much easier(and cleaner sometimes) to do it in the cab. Spools are great for straight line drag racing, but there hell in the front diff when your trying to turn a corner in 4 wheel! Thats why a selectable locker(air actuated or electric) now gets my vote, especially in the front end.