You can find walkable, safe neighborhoods all across the city, so it will likely come down to the location of your work, and the type of lifestyle you prefer (laid back, in the scene, family life, etc.). I live on the west side myself, so I'll speak to this area.
What is a Concave Wheel? Concave Technology takes the center of the wheel and dips inwards to give it that bowl effect. Rather than exaggerating a bigger lip for the back wheel, and a smaller lip for the front. Concave wheels emphasize the concavity of the rear wheel to differentiate from the front wheel.
Concave is an adjective describing a surface that curves inward, like the inner surface of a sphere. Its antonym, convex, describes a surface that curves outward, like the exterior of a sphere. In geometry, concave and convex refer to polygons. A concave polygon has at least one angle greater than 180 degrees.