Double pumper with automatic

Dp carbs are harder to launch hard on the street because you have to control the amount of open throttle. To much can be bad to real bad which of course translates into slow or real slow.

You can tune one to work and learn how to feather it, but it's a pain. The vacuum carb does it for you and does it well all the time.
The more radical the combo, the easier it becomes since grand-ma street driving is out the window and no longer a concern.