I had a great stay at Jason's place. It's obvious he knows what he's doing.. the room had everything I needed plus a few extra nice-to-haves, the place was very clean (and cleaned almost every day I was there; there were other check-ins/check-outs). Check-in/check-out were seamless and I never had trouble reaching Jason.
The Mission might seem a bit sketchy if you're not used to seeing urban poverty, but it's normal for the area. It doesn't feel unsafe, but you might be on edge a bit at first if you're not used to it.