I live in Mira Mesa, but on the other side, close to Caminito Santa Fe. My GF lives on that side, off Carol Canyon, so I am over there alot. I guess you need to tell us more about what you want. Do you have a family, are you renting a house or apt? are you commuting to somewhere or going to school? Roommates or just you? That kinda stuff.
I dont know jack about the schools, but I have heard they are ok.
The drive from the 15 to La Jolla/sorrento valley sucks. MM blvd gets really nasty at rush hour on that side. Everyone who uses the 15 to commute to SV goes through there. Same with Miramar. Budget half an hour to the 805.
Dont expect much street parking if you are in an apt.
The shopping and entertainment (movies etc.) are decent, but expect to commute for a good night life scene.
Crime, well, it is everywhere. Dont expect to keep your windows or doors unlocked. But it isnt like your gonna get carjacked everyday or anything. Be careful.
As for rents, they are all over the board. Some people have good deals, some people are trying to make you cover their bad RE purchases. Look around and you can find a decient rent. If you are single, young, and looking to save money, rent a room. There are plenty of them and a $550 a month rent is alot cheaper than $1200 for a 1bd/1bth.
Enjoy MM. Oh and it gets alot hotter on that side in the summer.