Precisely. Moab is a high traction adventure land for SUVS. You can do dozens of trails with zero pinstriping. The damage to the underside is all preventable by picking lines appropriate to your wheelbase. Bessie's been up the waterfall on Poison Spider, through Metal Masher, and a dozen other 4 rated trails with no damage save scuffed plastic bumper caps. Personally, that's the stuff I'll play in all day long vs senselessly shoving through alder thickets, and thorny brush.
To reiterate, I've been paid by Isuzu several times to prove that you can take a stock rig through all these trails with no difficulties, no stucks, and zero damage. Finally on the third year, I put a scuff in a bumper cover. That was it. The incredible traction in Moab totally changes what is possible. Got hours of excellent video of my trucks surrounded by lifted armored rigs.
To answer these questions to the best of my ability. The birfs were in excellent shape, no clicking, no visible wear, and just rebuilt the front axle about 3-4 months ago. The pass side broke but on the driver side I did notice that it has the newer spindle with needle bearings instead of the bushing solo. I could not tell if the driver side birf was original or not, but also appeared to be in outstanding shape. Never any clicking or visible wear. I'm not sure wear the breakage happened but I'd guess where I got a little wheel hop in the front going up an alternate obstacle on Fins n' Things. The vehicle is slightly modified: J lift, caster plates from Slee, 35" Dunlop mudders, ARB front with winch, SROR sliders, 4x4 Labs rear. Weighed the Cruiser on the way home fully packed and with 3 other passengers: 7,080 LBS.
Beno, the weakest link theory is great, but it would be easier if it were the flange rather than the Birf that goes first. Maybe some judicious grinding...?