Use Numbering from Specified BOMs
When you insert balloons and stacked balloons into an assembly, you can set the balloons to follow the item numbering of a selected BOM in the assembly under Balloon text source in the Balloon PropertyManager. You can then import the balloons into a drawing.
See SolidWorks Help: Balloon PropertyManager.
Parametric Quantities
You can set a quantity value in the Balloon PropertyManager that updates parametrically. In previous versions you had to add text outside of the balloon, then group the text with the balloon. The text did not update parametrically.
Custom Balloon Sizes
You can set the balloon size to any value using either the Balloon PropertyManager or . Custom sizes are available in balloons, auto balloons, and stacked balloons.