FWIW - I am leaving Irvine and moving to the Pacific Northwest after having grown up in southern California. I recently started a family and have no interest in raising my kids around here.
If you are okay with being house poor, you can probably afford to buy a house in Orange County. If schools are important, you better be willing to spend nearly a million dollars for a track home somewhere in Irvine, or set aside a significant chunk of money for private school tuition. Just took a look at Redfin or Zillow to get some idea of what you are going to have to spend. Where I am looking to move, I can get ~2000 sq/ft (3 bed, 2 bath) on a 5000+ sq/ft lot with good schools for $300-400K. The same in Orange County is going to cost close to $1 million.
The food here is pretty amazing and I am going to miss it. Southern California is an ethnic melting pot and you can get cuisine from all over the world here.
I am also going to miss the car culture. With so much disposable income in the area, and no moisture to destroy them, there are awesome cars all over the
The weather sucks. The temperate climate that I grew up with as a kid is gone. Blame it global warming or whatever, but now it is just hot.. getting hotter, and the humidity is increasing. Plan on having to run the air conditioning for a good portion of the year, even close to the beach. The much hyped "ocean breeze" is non-existent if you are more than half a mile inland. The change in weather is the primary reason that I am leaving. Southern California is a DESERT. There are major drought problems and they are only getting worse. Maybe climate change is going to prove to be a load of crap and I will be wrong, but I cannot imagine anyone with any sort of long term vision making a conscious decision to settle down in a desert that has to import its water to survive.
Ignoring the above, there is a good tech scene here. There are a wide variety of industries represented from straight tech like Google, to health care, to manufacturing, legal, literally any industry that you can think of has some sort of representation in southern California in general, and Orange County specifically.
If I was in my twenties and wanted to live in a house with a couple of guys and just ball out, this is a decent place to do it. There is always something going on. Or if I was still single and could spend half a million dollars on a condo, it might be worth sticking around here. But there are better cities to be single in, like Chicago.