A few folks here have bought in Temecula and there are a lot of old posts on that area here as well so I’m sure they can help if you had specific questions on certain parts of Temucula.
Buying a home and area is really personal and everyone is different based on what’s important to them. Major factors are probably where you work, where your friends are, do you have or want to commute, need a large lot? Looking for a new community (I think more kids are in newer communities; there was that old topic on less kids generally in more established areas like Del Mar, LJ).
There are too many variables so as I’ve told other people, the best recommendation is to just move to an area you think you want to buy in (or just move first to San Diego), then live here and see what area really appeals to you.
Sorta like a 1 hour interview, you can’t really learn the areas that well without spending more time living here.