No, it's not Mayberry and I wouldn't leave my car unlocked on the street, but compared to other cities Santa Barbara has always seemed safe. I think the crime statistics are mostly petty theft, tagging, stuff like that.
The gang "activity" is mainly harming each other (lol) and that happens mostly on the other side of the freeway (west of the 101), and around Milpas St, if you read the paper.
I have found the cops VERY responsive, when I have called about excessive noise or suspicious activity (like campers in the creek) on occasion. I say, go for it!