You're right, when an "open" diff encounters loss of traction, one wheel gets ALL of the torque/power. That's why one wheel spins and the other does not move. And it's true that you can fight this on the rear with use of the brakes or parking brake, but you have to feather the front brakes in 4WD to get traction. It's really noticeable on a sidehill incline, since the wheel on the low side will spin. That makes it dangerous and causes the front of the rig to slide down the incline. If you suddenly get traction, it's much easier to roll over. And driving on sand is a skill that fewer folks have than other types of terrain. If the sand is wet, it's easy to drive on and much like hard ground. But loose, dry sand will bury you to the axles if you spin the tires. I drive the local beach quite often, and see 2WD trucks buried to the rear bumper right at the entrance. A slow, steady throttle will get you thru more often than rompin' it. BAck to the open front, I've run a full spool to lock both axleshafts together. Since you only use 4WD off pavement, the only concern you have is extra stress on the shafts and u-joints from the spool itself. JSM84.
