I saw this two nights ago, and it's as good as everyone is saying it is. Namir Smallwood and Carrie Coon give such genuine, discomfiting performances. I've always thought of this play as a demented love story, and they play that angle with really profound subtlety. The set design is excellent, and the transitions are all handled really elegantly, in a way that doesn't at all remove you from the atmosphere of the show. At this point, I've seen every show Letts has written and while this will never be my favorite work of his, this production really takes the material to its highest possible level. Cromer killed it.
Also: I'm not normally the sort to notice something like this, but the lighting in the second act in particular is the best lighting I've ever seen in any professional show, ever.
My only complaint is that my sightline on the left side wasn't perfect. I saw most everything, but there's a dresser at the front of the stage that would occasionally block a subtle movement or something like that. Luckily, there was a mirror that ameliorated that problem to an extent (a really great design choice), but if you're considering going, I'd suggest you try and buy tickets in the middle section for the best possible sightline.