@Alex Stewart
Good additional notes brother, these should help formulate more pointed responses from everyone.
Like others in the thread, I am from SD, thus biased. Most from here, aren't huge fans of LA (10x worse traffic, bougie'er, more expensive, etc). But admittedly I don't know enough about the neighborhoods you are calling out. The OC I don't mind, and would absolutely move to Manhattan Beach or Newport if money was no object (ie 4M) and I wanted to be on the beach and surf everyday (I did in my youth, not so much anymore). Proximity to an incredible international airport like LAX is a big bonus, as SAN is a fraction of the size or capability or quality, unfortunately we have a garbage airport for America's finest city. That being said, like you I fly for work and have zero issues flying out of SAN, it is just a C+/B- compared to LAX or DEN or SJC or OAK and so on. If you fly mainly in the west, you'll have minimal issues. If you need to travel back to Ohio or east, it could be a hassle due to limited direct flights.
Taxes down here are brutal for high earners and expensive homes (you'd pay almost $50k/yr on $4M home, unreal), for sure. Getting worse. Politics in CA getting worse. Bums are getting significantly worse. We still have $2.20-$3.00 gas while I see folks posting online from TX paying under a dollar. Insane.
For SD and proximity to airport and that budget, La Jolla is probably the best for what you'll get, it's a top 5 zip code in the US for a reason. Less than 10 or so miles down the 5 to SAN. Coronado would be risky with the bridge. A secret spot to consider would be Point Loma, it abuts the airport, has old school charm, incredible new Liberty Station mega multi-use complex of restaurants and shops, and some awesome big remodeled homes, you could get a ton for $4M. I know a lot of families buying there. I live somewhat close to this area. Tons of property appreciation here too.
Also like you I am considering NV for tax reasons and getting more for your money. Major international airport (everyone around the globe wants to gamble!). No state income tax. Lower prop taxes, lower everything. It is attractive for all these reasons if you love the heat. 3000-4000sqft homes are normal, in fact quite small in many neighborhoods. Guard gated. New, clean. I don't know as much about Henderson but it is similar to Summerlin and has great new homes and schools (hearing a lot about canyons in green valley). If you look at northwest Summerlin (Reverence by Pulte) they are right up against the mountains, with some great views of the valley and the strip. Toll Bros on the south also has Mesa Ridge, near the mtns with great views and awesome master planned community. If you don't care about the beach, this region is a solid choice. Keep in mind most of these builders do not include pools for brand new builds, you need to DIY. Buying resell is the way to go for that, and usually locks in the lower property tax rates as well (higher on new builds, weird system).
Good luck man. Let us know what else you're thinking. Hopefully other folks chime in about the LA and OC hoods.