At the moment if I want to adjust a numerical value in the Inspector, I have to either: Manually enter a number, or Click on the Up/Down arrows multiple times. Please make it possible to click and drag up/down to continuously adjust values (basically the behavior you get by dragging an object's manipulator in the Viewport)
The default increment should be tuned based on the range of the slider so that a single click up/down gives a reasonable value, and so that you can easily click drag for large and fine movements within a relatively comfortable amount of mouse dragging.
Adding support for modifier keys to control drag speed would also be helpful (as we already have for clicking on the arrows).
Both I and my colleague independently found ourselves missing this style of input almost immediately.