I've lived in tokyo a year now and SF 2.5 years and I don't regret my move at all.
The guys lying in the street like that (even if not homeless) is actually culturally accepted. You see people sleeping in all sorts of places in Tokyo.
I won't comment on whether that's "good" or "bad" but it's definitely different than the US. I still heavily prefer Tokyo despite that (I don't see it that often in practice)
The worst areas are by far Roppongi and Shibuya. Admittedly, I don't go to Shinjuku as much.