First off let me say that I like your attitude and enjoy this thread.
I would not wander into the Heights, that place is scary, it's almost as bad as Brooklyn, which is...holy ****, you literally feel in danger there, even in broad daylight. I'm from St. Louis so I feel like I know when a neighborhood is hostile. The closer you get to the 160's it starts to feel like Conrad's "Heart of Darkness" like I'm getting deeper and deeper into this horrible place and I will not get back out with my sanity intact.
There are no safe pockets at nighttime. Ever been to Chicago? That stuff spills over at night. I'm sorry, but you said Washington Heights and I had to jump on that . I took a Subject GRE over there one time and had to walk all the way through it to get back to *erghm* America (I'm joking, don't get all peevish SDN). I just would not want to live in an area where I feel besieged by a surrounding hostile neighborhood.
Can I say DRAMATIC? Many parts of brooklyn are very educated/professional family oriented neightboorhoods that most upper middle-class people can't afford to live in. Have you been to park slope, brooklyn heights, bay ridge etc etc? They are super trendy and have tons of cafes and restaurants. A one bedroom in park slope is like $2500 per month. Please don't generalize and jump to conclusions from one experience you had.