Loved it.
Fans of hoofing-in-the-slats are in for a real treat.
I understand frustration at the ending to some extent: I realised what was going to happen with about 5 minutes to go, and felt something approach actual grief. However, by the time the credits rolled, it all made perfect sense. There are no neat resolutions, because life isn’t like that. Thematically, it’s totally consistent with the murder going unsolved.
However, embedded within that, you have the over-arching theme of struggling towards acceptance and forgiveness, as illustrated by Mildred and Jason’s truce.
I was also hugely impressed that they managed pull-off the seemingly impossible feat of improving a film featuring Frances McDormand – by throwing in Clarke Peters half way through!