The major difference between the DCD771C2 and the DCD780C2 is in the power and speed of the drills. The latter has a higher power output of 350W as compared to the 300W of the DCD771C2.  The DCD780C2 also has an increased speed range of 0-600/0-2000 RPM compared to the 0-450/0-1500 RPM of the DCD771C2. The DCD771C2 on the other hand has 16 clutch settings vs 15 settings available on the DCD780C2. It is also the lighter and more compact drill of the two models.  The DCD780C2 comes with a belt hook, which is not provided in the DCD771C2. If you have any questions regarding this DCD771C2 vs DCD780C2 comparison, you can comment down below or reach us from the contact page. We are happy to help you.