I left off somewhere in season 3 about a year ago and still need to catch up. The two leads are astounding and the way it captures the period setting and social aspects are noteworthy. It's good stuff but has peaks and valleys.
Sometimes very interesting plot lines go on slight hiatus or get dragged way out, often with good payoff, but sometimes not. Still a very entertaining show that is easily recommended, the highs are very strong.
Been meaning to try Black Sails myself now that you mention...
Here's the Onion A|V Club on the show after season 3.
With each passing year, The Americans has faced skepticism that it will be able to continue its near-flawless balancing act: a juicy and complex spy thriller on one hand and richly drawn character study of a marriage and troubled family on the other. Each year, showrunners Joe Weisberg and Joel Fields manage to find bold new ways to continue the story without sacrificing either nuance or a grounded sense of reality, as Keri Russell and Matthew Rhys bore ever deeper into their characters knotty thicket of marital issues that suffuse every mission and miasma of subterfuge.