There's tons to do on Hayes Street which is full of boutique shopping, restaurants, cafes, coffee shops and a few bars. It's lively, fun, and friendly. I loved having stuff to do just outside my door. There's a sweet little park on Octavia where people bring their dogs, kids, and picnics. Recently the city has installed some popup trucks/trailers with ice cream, a butcher, and Ritual Coffee. If the arts are your thing, then you can walk to the Symphony, Opera, theatres, and Asian Art museum.
Hayes Valley does have it's share of section 8 housing, so caution should be taken when parking and walking at night. That being said, I lived literally across from one complex for 4 years and never had a problem.
All in all, I would highly recommend Hayes as a place to live for San Franciscans new and old.
Also, Hayes Valley is super central, easy to catch a bus, and near Fell St. and Oak St. -- big thoroughfares in SF. Also, a relatively easy walk to Civic Center Bart (for commuters/going to airport), and the new freeway on-ramp to 101/BayBridge is very close, if you want to get away from the city. Easy walks to the Haight, Duboce, and the Castro. Proximity to the panhandle and Golden Gate park is a big plus too.