It really depends on which part of SoMa, and on how you personally are affected by trends of an urban neighborhood. I'd say during the day, nearly the entire area is fine. After 7-8pm, *some* areas can become sketchy. Even though it's gotten better in recent years, I'd stay clear of 6th street. But 5th street has some very expensive hotels and apartments, as does 4th street since at Market it becomes Powell. On 7th, 8th 9th st. from Mission to Harrison you have to feel it out but generally living there is fine. The alleys between Minna and Natoma can be a little sketchy sometimes but again it depends on what you're doing. I have a couple of friends who've bought homes in those alleys and they love it! I'm actually from SoMa and it's my favorite SF neighborhood. Just make sure you're vigilant when walking around late and if you can, take an uber or a taxi to and from your place if the trains have stopped running. Feel out the landlord and the building. (I actually lived on 6th street back in the day and even though the neighborhood was *definitely* sketchy the building and the landlord were great.) You just have to feel it out.
