If he opened in North Park he would be killing it and would have the magic money machine. The place would be packed every night. Point Loma near the Sports Area would probably also do well. Downtown could work though the rent would likely be too high as they originally said they were going to Barrio Logan because rents in the gas lamp were too high for their business model. Any where in central or coastal county and he would be mobbed by customers demanding he take their money. Honestly, North Park (just north of Balboa Park) or Hillcrest would be ideal in my mind. Centrally located for both north and south county residents, walkable with a lot of foot traffic, neighborhoods definitely gentrifying, but with a clear history going back to the 1920's.