What's being called "insertable 4x4" can be equipped in both Ferrari's mid-engine and front-engine vehicles and will only be activated if the computer senses a loss of traction. However, unlike systems utilized by Lamborghini, Ferrari drivers can choose between traditional rear-wheel- and the four-wheel-drive when and where they wish.
The new system functions much like a conventional gearbox, however, a secondary clutch is joined to the crankshaft, which will only be engaged when the system detects a slide or excessive wheel-spin. When it does, power will be sent to the front wheels to right the vehicle. According to the article, the system works very well, however the all-wheel-drive system can only be active for a short amount of time at high speeds, as mechanisms in the system are prone to overheating. Whether or not this problem will carry through to the production models was not addressed in the article.
When it comes to outright traction, all-wheel-drive is clearly the dominating drive train, however, with the additional weight and complexity of the system, we hope that Ferrari is willing to take the inevitable flack that will come from their core clientele of drive train traditionalists.