I have followed this thread with interest. As resident of Carlsbad living in the 92011 zip code I can tell you that we have loved every minute living here. We have friendly neighbors who welcomed us when we arrived. One neighbor had a party and invited all the people living here so we could meet everyone. I have never lived in a better neighborhood.
I disagree with your assessment that there are no families with children here. There are many young families and they are friendly and active. There are also retirees, families with teenagers and singles. I think this type of diversity is a strength in any community.
There is easy access at several points to the freeway. employment and shopping. The beach is very close even if you live east of I-5.
I do wish there was a bit more restraint when talking about individual neighborhoods. Each neighborhood will be different yes, not better or worse but different.