A Detroit locker is just that "locked". When you are on the throttle the unit locks and will stay locked period. They are extremely strong and reliable. The difference between the newer Detroit units and the old style is Eaton redesigned them and they are now called "soft lockers" they perform just as well as the old bullet proof rears but they are much quieter, the signature ratcheting noise is no longer noticeable and the unit actually un-locks in a corner (if you are NOT on the accelerator and just coasting) to compensate for different inside and outside wheel speed. I absolutely love mine and feel there is absolutely Zero draw back vs. the more popular Tru-Trac selection most make for its limited slip capability on the street. I wanted a fool proof 100 % posi rear so thats why I chose this route, again with no regrets. My tires have never worn more evenly, flatter or better.
The limited slips e.g. stock Sterling is okay with the bone stock power level but once the high horsepower tunes get installed they suk but quick, torque overpowers the clutch pack in no time. The aftermarket clutch material type limited slips may offer a longer life but w/ the race tune power and a heavy foot it will be a matter of time till they fry and become the infamous one wheel peel unit. Let's face it any clutch friction material has an absolute torque handling capability, period. I've heard good things from most about the Tru trac rears, but I have also heard from reliable source that they do not always perform as advertised particularly while off-roading but applying the brake tricks the unit and can get it to distribute the power evenly again.
So to paraphrase; the tru trac is a Torsen or TORque SENsing unit that needs feedback to operate properly. The Selectable variants (via switching) are typically either electronically or pneumatically actuated to select between either an open or a locked unit. Clutch type limited slips like the stock 10.5" Sterling or Eaton posi LSD uses a friction material and springs to control power to both wheels. And the Detroit Locker is full time posi traction rear end that delivers 100% of the torque to both drive wheels, as long as you are on the power.
