Price - $40 to $60 us dollars. But factor in a few drive shafts with that, as front diff's are brutal on them.

Alot of people prefer front ball diff's becuase it makes the car more forgiving. Generally a car is more inclined to push with a front diff and oversteer with a front oneway.

It all depends on what you run and your driving style. If you brake alot you'll need to learn how to roll through corners instead of brake/power out. The straighter you keep your wheels the faster your car is capable of going. Thus why the front one-way is such a great advantage in mid-high traction conditions. Basically you can have the dual rates at 65% and have the same amount of steering that you had with your ball diff up front and the dual rates set at 100%. The less your tires turns the lesser the friction, so there is less time scrubbed each lap during cornering.