Overall a nice place to stay.
We were unfortunate that at the time of our stay, something, that we assumed to be machinery in a nearby building, was making the whole place vibrate. It was nothing dangerous, but we could hear and feel the vibration at all times. We stayed most of the time out, so it didn't bother us that much. But it was harder to sleep.
It was very clean, and it was very close to a lot of nice restaurants and nice places. There are a lot of homeless nearby, some using drugs, so be careful. However, that's a problem of the city of San Diego, not of the hosts.