I believe the "detroit locker" is derived from the stance of the "posi unit" ergo; continuously locking diff. I don't exactly know where the name is from, but I know that GM has in some shape or form name-plated that to their vehicle monocle,but, I could be wrong here. I think in a lateral form, depending on vehicle manufacture, they make up some variation of different rear end names, to which have and serve the same purpose. detroit locker, posi track can be submissive at best, but in essence are just that; locking differentials.
Equa lock as I said, is merely a unit in which one wheel drives one singular wheel until it begins to slip in which the locking mechanism automatically locks the other wheel to help aid in traction, which does not require any driver control ( like air lockers and such do) the pros? Great, better forward motion traction in a straight line. The downside? Somewhat adverse oversteer, and a greater premature tread loss. Either way you cut it, it is better to have a purposeful "locking differential" then not at all. Better performance overall, but does helm a greater loss in other areas, which may, or may not , be a concern for most (simply cause it's just funner haha)