Yes, I did nearly destroy the entire internals of the front diff one day on the trail, and I do have the Cast Iron front. Here is what happened: Going up a rocky, loose dirt hill climb with a slight turn to the left in it, got hung up with the front tire on a rock, and the rear tires hung up as well. I backed up a little, and tried a different line, which allowed one front tire to loose contact with the ground, as the truck tried to gain traction it slid slightly and then the airborn tire made contact with the ground and the truck bounced to the left and jammed the drivers tire into an embancment which is what probably broke the tie rod. I am sure the quick drop and sudden stop of the tire is what broke the CV axles. Also the force of the V8, with the TCase in Low and front diff locked aided in the front going boom.
Now contrary to 4speed's situation, my drivers stub shaft didnt break, only a slight twist in the teeth at the inboard side of the shaft which then broke the spider gear it rides in, inside the carrier. Also the force of the V8 is what lead to the sheared pins on the eLocker.
Every offroad situation is different. I have wheeled this particular trail many times and never before had to even pull which line, let alone a full faiure of the front end.
I will say though, that the most likely culprit of front diff fauilures are from too aggressive driving style. The H3 has an amazing traction control system, and will get you through alot of things I have found. And have now adjusted my driving style to reflect that. I recently ran a trail near me this past weekend entirely in 4High Lock. And in several spots I used to put in 4Low to get over rocks and ledges. I noticed by keeping the RPM low (max 2000) the traction control would kick in and send the power to the wheel with traction and pull me up and over obstales with realative ease. Is this proper? I am not sure, maybe some one else with more technical knowlege will chime in, bit it did work for me. It is also the same principle I applied when wheeling in Moab in April. Now the terrain on the east coast is WAY different than the rocks out west, over here it is alot of loose granite and loose dirt on top of rocks and ledges so traction is for less than desireable. Which is why alot of us East Coasters tend to be more aggressive with the skinny pedal, we are just trained that way and it is needed alot here.
The lack of front end upgradeable parts really doesnt help out those of us who do need to be more aggressive with our trucks. RCV axles, BulletProof tie rods, etc, only send the potential faluire points further down the driveline. The question becomes do they help prevent those falures or not? The small size of the diff is also a weak point for those of us running larger than stock tires. I am sure that under "factory" conditions everything would last a long time. But none of us want to run a full factory truck. Personally I want to run a 37" tire on a Rancho lifted truck. And thats so I can get more clearance front, rear, and center (I have a long H3T). But by going to a 37" tire, I know the potential for breakage is multiplied exponentially vs a factory set up. And no disrespect to Bebe, Recon, or 4Speeds builds, but I am do not want to devieate that far from the original design until the original parts are no longer available. Which might be sooner than we expect. Remember, most of the H3 drivtrain is specific to the H3. I have been spending soem free time at work trying to cross the part numbers to componants and coming up empty.
For a true upgrade, a full conversion is the only way to go, at this point.