Nice, but those have barely any tread! I've read a lot online about folks using Vibrams during Tough Mudders and they slip-slide around because of the lack of tread. The KSO Trek looks better, as they have more texture and treading on the soles, but they're $80.
The ones I've heard are the best are the Spyridon because they're made for trail-running - better tread and thicker sole so you can't feel rocks and roots:
Vibram FiveFingers - Trail Running Minimalist Shoes for Men – SPYRIDON LS | Vibram FiveFingers