I just finished replacing my lower control arms with new bushings & ball joints, and guys, I've got to say that-
1. If you have at least 90-100K miles on your car; and
2. If you value great handling (like BMW's); and
3. If you've spent (or are going to spend) big bucks on wider wheels, performance tires, shocks, springs, strut tower bars, rear sway bar, etc.
Then you're really missing the boat if you don't also renew your front bushings and ball joints. Amazing how much difference they've made!