I'm a huge fan of these slow-moving films. "Columbus", "Driveways", "First Cow", they're some of my favorite atmospheric, moody films, so if you're not into that, you're going to hate this one.
People are ragging on Michelle Williams' sculptures; it is true they're not Michelangelo or Chihuly, but the "quality" of her sculptures isn't the focus of the film. I don't think most audiences would resonate with "Showing Up" unless if you're an MFA student who's absorbed in the mediocre world of academia (and usually absorbed in that world for the sake of stable income). The focus is the culture of that environment and Michelle Williams's character just... going through it.
I thought it was fantastic. My only problem was the heavy-handed symbolism of the injured bird flying away at the end, felt too full circle for me, but I also appreciate Kelly Reichardt's making the films she wants to make, and if she wants an injured bird flying away at the end of her movie, she gets to have it.