I'd give it 5. There aren't many shows that I follow and even then they're mostly comedies. It's probably the only drama on tv I like. Bill Hader is also kills it as Barry.
Barry is a testament to a man, a contract killer, who tries over the course of a series to change his lifestyle, mindset and worldview and ultimately, he fails in doing so.
Very much a sad, comedic-tragedy if you break it down.