[theBroken]

As far as durability you can't really say one is better than the other. Everybody form ATV's to crazy 1 ton offroaders use both and neither ever complain. Each will have their certain amount of failures, anything mass produced will. I would give durability to eaton but just slightly. They have their lockers in more vehicles than anybody else so the handful of E-locker's I've seen fail can't be compared to the zero ARB's I've seen fail because 70% of the 4x4's with push button lockers are eatons. You can't compare them numbers.

Now as far as longevity & durability, the eaton E-locker falls far short of the ARB by a long shot and here's why. Metal! Simply metal! In any mechanical piece with lubricated parts, eventually it will fail. The reason it fails over time is because the metal to metal contact slowly breaks down. This can be seen when they are in the form of shavings and metal dust. In a diff without a locker them metal shavings get ground down over and over again till they get drained out in your fluid when you change it. This is true for a ARB locker, but not in a E-locker. The #1 reason a Eaton E-locker will not outlast a ARB air locker is because the Eaton E-locker uses a magnet to engage the locker where a ARB air locker uses compressed air. So over time all them metal shavings and dust are not just floating around in the gear fluid but instead its sticking to the magnet. When this happens it makes the face of that locker turn into sand paper which then eats away at the pins and locking mechanism causing it to fail prematurely. Changing your fluid often will reduce this greatly but under the same circumstances over time the ARB will outlast a Eaton E-locker.

Now this may fail at 100k or 300k but you get the idea.