I had a nice couple of weeks staying at Charles and Emily's place when I first moved to SF, while looking for a place to live long term.
The apartment is modern and comfortably furnished. While a studio, it's quite spacious and has plenty of room for one person or a couple. All the equipment is modern and recently remodeled.
The neighbourhood is quite out of town, but it's only a 15 minute walk to the 24th and Mission Bart station which will get you downtown quickly. The neighbourhood is nice and peaceful.
Charles and Emily were very helpful and responsive with any issues I had. The apartment upstairs would sometimes make a lot of noise running around which could be heard very loudly on the ceiling, but it was never after 9pm so was no problem for sleeping.
I would definitely recommend this place to anyone looking to stay in the Bernal Heights area.