Not stubborn but very smart & independant which may come across as stuborness to some people. They should be enrolled into obedience classes, any breed should but especially an active dog who isvery independant.
Overall they are a great dog for the experienced person.
They are very versatile dogs, able to do just about anything & everything.

If you can train dogs & have the time for proper exercise I'd reccomend an Aussie in a heartbeat.