I spent my entire childhood there. Of course things have changed a bit but the heart of Olivenhain was that it was horse country. The community has many horse trails that weave throughout. I haven't been back there for a while but the last time I was there I noticed that many of the horse corrals have been replaced with swimming pools and tennis courts.
I love the country feel there. I spent my childhood outside climbing trees, hiking through the sage brush, and swinging over the ponds hidden throughout.
I think I had a good education. It is my understanding now there is a good elementary school there. I don't think you can go wrong with a move to Olivenhain.
The Encinitas community is great for kids too. There are a variety of pre-schools for you to choose from using a variety of teaching styles to the commonly know Montessori to the lesser known Waldorf. The community is very aware of being eco-friendly and there are many shops that sell eco-friendly items.
If you love eating healthy, I recommend you going to Ky's located on the 101 south of the campgrounds.
I now live inland, but I continue to drive my family all the way to Encinitas to enjoy the beaches there. You can't beat Moonlight beach. It is extremely child friendly. It has a fun playground and the lifeguards have their main tower there year round. Moonlight beach has a fantastic snack bar as well (run by my friends).
I am excited for you. You will love this move!