Center diff?

[fonecrusher1]

Is the purpose of center difflock on the 3rd gen purely to enable the vehicle to be driven on hard surfaces in 4wd fulltime?
Does it actually give an advantage offroad?

[Apache]

Not quite. The centre diff means it can do that. The diff lock means power is delivered equally to the front and rear axles thus giving better chance of traction off road if one end of the vehicle is slipping.

Its not a good idea to use ANY locks on grippy surfaces.