[JavaBrewer]

I just caught your requirement for older-established neighborhoods and no/little HOA and Mello Roos. That pretty much wipes out the area's I was going to suggest.

Scripps Ranch (I lived there 8 years b4 moving to SM), Carmel Valley, RB, Poway all have good school districts but you have to move into the right neighborhood. For example San Marcos schools North of highway 78 consistently score 50% lower than the schools on the South side - which score in the top 5% of the state. So moving into the right area is important.

I think Rancho Bernardo and Poway are good bet's for what you are looking for. I really like Scripps Ranch but older homes there are small and are on small lots and will command ~ $650K. I would say the best option is to rent for 6 months and take your time to look around.