Where do you work? 4S Ranch is in Rancho Bernardo and La Costa is in Carlsbad. Quite a distance. I live near La Costa Greens and I love it here! We are 4 miles to to the beach and Legoland.
4S is more inland and tends to get hotter in the summer. But if you work near 4S area, you might want to live nearby because the I-5 traffic is pretty bad every day coming and going to Carlsbad.