The diffs lock per a 3-position switch, basically 1) both unlocked, 2) front locked, 3) front and rear locked.
The truck is definately 'at home' in the wilderness, though not necessarily on a rock crawler course. It does very good handling natural terrain, mountain trails, underbrush, singletrack, etc.
http://www.youtube.com/watch?v=oxnKjVfPH1I
http://www.youtube.com/watch?v=luBKYVfQJ30
http://www.youtube.com/watch?v=lA8TnezIfx8
http://www.youtube.com/watch?v=3dDgsZQce3g
http://www.youtube.com/watch?v=GORwUVrZsWI