Terri, I can only speak from my experience with La Costa Meadows, but the parents are very much involved, which of course is the key to success no matter what district your school is in.
Carlsbad just agreed to build a new high school, so if your kids are in elementary school now, it may be completed before they need it. Also, San Marcos high school is definitely improving and increased parental involvement is one reason. Who knows, maybe there will be a new high school there too within the next 10 years or so. With all the new houses in San Elijo, I would think they would need one by then. So there is a lot to consider. But through 8th grade, you would be safe with San Marcos, Carlsbad or Encinitas schools, one of which you would get living in Carlsbad.