Joyce's place is just perfect for a solo traveller. Room is bigger than it looks on the pictures. And the shower and ensuite facilities are awesome for this price.
The only con is that sofa bed is not really that confortable. If room had a regular twin bed with a good mattress I could rate it 12 out of 10.
I spent a whole week on this room and my plans have all been exploring San Francisco. It takes about 30 minutes to get to the West Oakland Bart station and then 15 more minutes to the city center. McArthur Park station is closer (about 20 minutes walk) but train takes a bit longer to get to San Francisco. So it is up to you.
I had no problem with the WiFi in the whole week. It is true that signal is a bit weak, but was sufficient even for some work stuff I had to deal with.
Neighborhood is safe. You have to be cautious as in any other place you don't know. But there is really nothing to be afraid of, even at night. I honestly think that some areas around Union Square, where many budget hotels are located in San Fransisco, are way worse than this part of Oakland.
I really feel lucky for having found Joyce's place to spend my holidays. I would come back to her place again if ever back in San Francisco.