This area of the mission is certainly lively - I stayed there before a few years back and obviously the food is awesome! Jason's place is great and very close to bus / BART links, however as everyone knows San Fran has a drastic homeless problem like any major city.
In hindsight I probably wouldn't stay in this part of the mission again as a lone lady travelling because walking around to and from the BART I got harassed a lot. I used the public transport but would always get an Uber back to the apartment after dark. The 16th Bart isn't the greatest place to frequent with luggage and waiting at the bus stop alone wasn't a great experience for me. If you're travelling with a friend etc it will be fine but for me it was really hard to leave everyday without getting approached. I actually made friends with rose and TJ who live in a tent on Folsom street near the apt, so please do look after them if you stay (sometimes people just need a friendly face).
Jason's bed was comfy, and his hospitality seamless. If you're looking for somewhere to stay in the mission - stay here. Clean, comfortable and equipped with brekkie/food & drink I was certainly set up for the day. I loved that the apartment was close to exploring Valencia etc - Tartine is amazing (well worth the line but Monday's around 9.45 the line was shorter) and go to the Chapel/Vestry if you get the chance as the food was amazing and it is an awesome music venue!