This is a potentially powerful tool, but it needs some basic upgrades to make it easier to use.  The first is auto-range detection.  VW should be able to auto-detect the range from lowest to highest - then let me decide 1 of 2 options - Stepped or Gradient.  (User Defined Range option should remain.)   For Stepped - I would then select the number of steps - say 5 - and VW would auto divide the objects based on the auto-detected range.  I then could assign the graphic attributes of each