Mark's place is really lovely and the location can't be beat -- Central to most of the activity in The Mission and just a couple blocks from the BART (and bike share docks, which is how I tend to get around downtown SF). He himself is a gracious host and great to talk to. Mark was out of town when I arrived - his friend Aaron showed me the ropes - but was very communicative and made sure I was able to successfully check in. All in all, this was one of the best Airbnb experiences I've had -- highly recommended! ... and oh yeah, the rooftop terrace needs to be mentioned -- great views of the skyline.