Based on my experience with it, I would not recommend the Salsa Down Under rack.

I bought it just before doing the Great Divide last year, and it snapped halfway through the tour (actually it broke after I abandoned the Greate Divide route for pavement in Colorado... but I had already done the incredibly rough dirt/rock roads in New Mexico by that point with it.)

It's the only rack I've ever had a problem with.

Edit: I was using the rack on a Salsa Fargo.