It would be very useful to change the value in unit steps, click on the small triangles in the sides of field as shown in the attached example.
The incremental value step (1, 0.1, 0.01, ...) could be defined in the general preferences.
Alternatively it could change the value with the mouse, hold down LMB and drag to left or right.
Hold Ctrl to snap to the discrete steps while dragging or Shift for precision input.
