Western Addition is comprised of a number of smaller, diverse and distinct neighborhoods: Lower Pacific Heights, Cathedral Hill, Japantown, the Fillmore, Hayes Valley, Alamo Square, Anza Vista, and NOPA. It's located centrally and bounded by Van Ness Avenue on the east, Masonic on the west, California Street on the north, and Fell or Oak Street.
Although WA has a reputation for high crime, but I've never felt threatened, or been victimized. http://www.trulia.com/crime/ I feel safe but there are definitely streets I would avoid after dark. Despite this, there's lots to like about Western Addition, so much so that I recently invested in a property there.
I moved to the neighborhood from Hayes Valley in May 2011, and live at the far north east corner (Cathedral Hill). I love being so centrally located with access some of San Francisco's most fun and interesting neighborhoods. It's easy to get anywhere, by bus, on foot, or by car.
Lots to do nearby. Great selection of Asian restaurants: shabu-shabu, Korean, Japanese, Sushi, Noodles, Izakaya, Chinese. I walk over to Fillmore for Indian at Dosa or chicken and waffles at Gussies. Polk St., and the Tenderloin have lots of nightlife options. Safeway is within walking distance, and there are two Japanese markets on Post. Japantown mall is always fun, plus there's the Kabuki theatre and spa.
My neighborhood is very residential, mostly condos and coops. I have lots of options when walking the dog. There's are two off-leash parks within two blocks. Is cooler, more foggy sometimes when I get off the bus from work in Soma.