Keep in mind the old clutch disk based LSD is not a full locker and will still loose traction with an open wheel. The E-locker on the other hand is 100% full lockup when engaged (think full spool) with zero slip even with a tire in the air. Of course the downside is the electronics disengage the E-locker over a certain speed. Not sure why Ford chose that logic other than to keep down warranty repairs trying to engage the E-locker at highway speeds

Also just an aside, but this statement "true clutch-style mechanical limited slip differential" is sort of an oxymoron. There are two types of limited slip differentials, the clutch disc style and a mechanical style. The clutch disc uses the obvious series of friction disks to enable lockup, while a mechanical LSD uses compound gearing to enable lockup (no discs). Both combine that functionality with the diff fluid which assists in lockup friction.