I visited San Diego and loved it. I stayed with a friend in Santee and just drove to the beach when I wanted. What's not to love? Beautiful weather, beach, amazing mexican food. But then again, I was only there a few days. Nothing more than a tourist. So your input is really awesome, thank you!
As for New York, I'm a native New Yorker, 31/m/look white, but actually hispanic. I grew up in the city, moved upstate to the country for a while, then back to the city. So I have a good idea of both extremes in NY.
First I'll start with the city since it is where most people would want to live. For starters, it is EXPENSIVE. You won't find anything bigger than a shoebox to live in and rent is insane on the actual island. Most people (like myself) live outside Manhattan in one of the boroughs. Even those are getting insanely expensive with gentrification.
New York is so white washed now, gangs and crimes aren't really a concern in Manhattan, again, due to gentrification. The only neighborhood I would stay away from would be East Harlem, I lived there for about 4 months, and it was ghetto. Cop cars everywhere, batshit crazy junkies sleeping in the streets, that is the only place I've seen gang violence. In the summer, it isn't uncommon to hear gun shots ring out in the middle of the night. Although, people say it is "up and coming" which is just political rhetoric for "we are trying to kick the blacks out and raise the rent prices".
As far as weather, it gets brutally cold in the winter. It hasn't gone above freezing except for 1 day, in about a month. Cold dry wind just cuts thru you when you walk around the city. In the summer, it gets hot and humid, not like beautiful beach weather. Muggy and sticky. Also, the whole city in the summer smells like trash.
It is loud here 24/7. Cars honking, people yelling, sirens blaring. You get use to it, and just zone it out most of the time, a majority of people just walk around with headphones on. The crowds can be insane, especially in midtown. So many people! You can't help but bump into people while walking. Most outsiders say New Yorkers are rude, they don't usually say 'excuse me' if they accidently shoulder bump you. It isn't that we are rude, it's that, we are always in a hurry. Go, go, go, nonstop. That's life in New York. Also, the trash, the city is unfortunately dirty. Trash everywhere, on garbage pick-up days, people just put their garbage right on the sidewalk. It's completely common and normal to see.
Public Transportation is what most people use to get around, the trains are constantly under construction, but they work for the most part. Rush hour on the trains is a nightmare. Like sardines being packed into a crushed tin can. Everyone pushes and shoves to get on the train. At night after rush hour (I work nights, usually get out at 2am), the only thing you have to worry about is the smelly trains where the homeless sleep. I've never had any issues late at night with being mugged or anything. My commute is about an hour door to door, usually standing the whole time if it's rush hour. You spend a majority of your time on the train. You end up memorizing all the stops and signs, the only thing that changes are the people.
As far as life in the country, it is the complete opposite. Everything is more spread out, it is quiet, a slower pace. You actually hear birds and see trees. But there is absolutely nothing to do! Unless you are an outdoorsy type who likes hiking, fishing, mountain biking, etc. there is jack shit to do in the country. The commute to the city is nicer, although a bit longer, and living in the country is much cheaper.
I'm not trying to dissuade you from moving to NY, it really isn't too bad once you adapt to the routine and fast paced life style. New York City has everything you can imagine. All types of food, bars, people, things to do, places to see. You can't possibly be bored here.