rear brakes only

The front brake has by far the most effective stopping power. As you smoothly apply both brakes the weight is transferred to the front and off the rear. Braking with both brakes should always be done in a straight line. There are cases where it's best to stay off the front brake, in sharper turns, gravel, steep downhill grades, etc. The rear brake is best in slow speed maneuvering (trailing brake) as it stabilzes the bike. Anyone who has ever taken a GOOD motorcycle course knows all this.

Any rider that uses only the rear brake under every condition is totally ignorant and will eventually get into trouble.

Evidently Honda and Moto Guzzi know that some riders don't understand braking, that's why the GW and some other Honda bikes have integrated braking. Guzzi's the same.