Carmel Valley is just north of Sorrento Valley, just southeast of Del Mar, directly east of Torrey Pines. The weather, if you ask me, is perfect. 70-75 almost every day in the spring, summer, and fall. Overcast less frequently than right on the coast (La Jolla). Overcast only a few days a year more than Scripps Ranch (which is where I used to live, and which is just southwest of Poway). A tad less cold in the winter than Scripps Ranch. If you like it warmer in the summer than 70-75, then further inland (Poway, Scripps Ranch, Tierrasanta, Rancho Bernardo etc.) would be more to your liking weather-wise. The weather in San Diego and north county is determined mostly by how far you are from the ocean. Less than a mile, lots of overcast and a bit cool in the summer, 1-4 miles mild summers, 5-10 miles warmer summers, more than 10 or so miles hot summers.
Carmel Valley schools really are the best in the San Diego area (except maybe Rancho Santa Fe) and some of the best in the state. Test scores are very high, college attendence rates are very high for high school graduates, parents are very involved, new schools are opening to keep up with demand. Campuses are clean and safe.
Carmel Valley in general is very safe. Less crime than most places (including Poway, according to Yahoo Neighborhood profiles. Found one!).
There is plenty of shopping and other businesses close by. The beach is a very short drive.
The area wasn’t built up until the mid ’80s, so almost all the houses and businesses are newer than that. I suppose some people like that, and some people don’t.
It’s a very suburban feel, without any of the hipness of Del Mar or artsiness of Leucadia or bohemianness of Ocean Beach or young-hangoutness of Pacific Beach or rusticness of Poway or urbanness of downtown or ritziness of Rancho Santa Fe or oldness of Escondido or Hootervilleness of Ramona or enlightenedness of Hillcrest or lemony freshness of Lemon Grove or… well, I could go on and on. Suffice to say that it’s very plain vanilla suburbia. But it’s upscale plain vanilla. And did I mention the weather is nice?