I would have liked to try the chains. It's something I've considered for my truck (at least having them available to put on). But, I need to run wide spacers in order to make them fit with the 35s. Even with the body lift, I still touch the inner fenders on hard compression.
Josh has the 4 pinion diff, like I did. In this case and in mine when I broke, it wasn't the spider gears but the ring gear that broke. The carrier that the ring gear bolts to deflects/flexes just enough and the pinion jumps and breaks ring gear teeth. I got a good look at mine when I took it apart. Obviously, this may have happened on the reverse descent, or it could have happened during one of the climbs. A spinning wheel that suddenly grabs traction sends a shock load through the system and in this case found a weak link.
I'm convinced that as the 4-pinion type 100's get used/wheeled/worn more, they will break at the same rate as the 2-pinion. The carrier of the ARB or TJM (what I have) is much stronger/ridged than the OEM carrier and doesn't allow for that deflection. Plus, most of the time the person is re-gearing or at least installing new gears at the time of the locker install and more preload is set-up. That also reduces the chance of the pinion and ring gear separating.
You guys who have done this as PM on your 100 did it right. I had to learn the hard way. Nothing motivates learning something new like having to spending money.