Depends on what your doing. Racing, I’d want the default to be locked. Wheeling, I’d want the default to be open for that trip back home on the blacktop. The more I think about it, if you have selectable hubs (I have slugs) and they were in the free position, you could unlock your wheels even if the diff is locked right? If that’s the case and the extra $$ doesn't matter, competition all the way.