There are two things you can do to speed things up a bit:
1. Remove the entire wiper arm assembly and thoroughly clean all pivot points, followed by relubrication (grease).
2. (If you're handy with electrical/electronic devices) - Remove and disassemble the wiper motor, clean the brush contacts and replace the brushes if worn.
My assembly now operates approximately at twice the speed from when the car first came home.
Before:
After:
