Carlsbad is nice but the traffic in the North County is horrible. Don’t do it. How horrible is traffic in the North County of San Diego? As bad as LA and sometimes WORSE.
Linda Vista is not my cup of tea. South of Genesee in LV is one of the most impoverished and worst crime areas in SD. The Kearny Mesa area (north of mesa College Drive)of Linda Vista is pretty decent. The middle and high schools are terrible. Kearny High is GHETTO.
Serra Mesa is a nice neighborhood. I live there and I love it. It’s centrally located and very conveinent. The valley is right down the hill. Everything is close by. There are quite a few reasonably priced nice SFHs for rent in Serra Mesa. Unforunately, if you have kids the high school is the same school as Linda Vista, Kearny High.
I don’t like Clairemont at all. Too many tweakers. Go with Tierrasanta or Scripps Ranch. A couple of other possibilities would be Rancho Bernardo or Rancho Penasquitos.