I had a head on (left front corner to left front corner, not a direct head on) with my ARB on Jan 1st 2004. I suffered ~$1500 worth of damage (to bumper, turn-signal lamp assembly, grill, front quarter panel, hood) while the other guy's Malibu was totaled.

I was stopped, the other vehicle hit me at a speed of at least 25 mph (his speed claim, I believe he was going faster) without even attempting to slow down before impact.

The airbags did not deploy. Probably because I was stopped before impact.

As for the "why people say the shrock or ARB is better than a brush guard" question - well, they are. I've hit rocks and trees with my ARB on the trail at slow speeds which have caused little or no damage to my X (in one case I tore a large section of bark off of a tree).

It's a winch bumper, not the armor of Ironman.

And don't forget that the bumper mounts onto the frame horns, which are designed to crumple in a high-energy collision. The front bumper won't prevent the frame horns from bending or twisting.

My guess is that the damage would have been much worse had you had a stock bumper or brushguard.