The way I explain it to people is HHN is an arena rock show: Highly produced, polished, more expensive, you get an assigned seat, and it's great
HOS is a local downtown theater alt band show: The theater is a bit rough around the edges, has more of a special charm, more aggressive, in your face, less polished and produced (not necessarily a bad thing)
I'll be honest, the last few years, HOS has lost some of its luster with Scott leaving. However, there were several years in the past where HOS outdid and even pushed past HHN