There were many things I liked about it!
The actress playing Lady M was phenomenal, and all the acting was strong. I really liked how Lady M and the other Scots spoke Gaelic to each other, leaving the audience as well as Siward (the English lord here to broker peace between Malcolm and the clans) and the other English visitors in the dark and only guessing at their intentions.
But I don’t think I’d recommend it, for a couple reasons.
One, while I can appreciate dark humor, there are times in the play when Grieg goes for a cheap laugh and ruins an otherwise complex and moving moment.
Two, although I don’t really support Lady M (though she’s much more sympathetic in the sequel than in Macbeth), Siward is…augh, just. I am so tired of “honorable” men and their good intentions.
Siward is there to bring peace and establish Malcolm as king, as per orders from England. And initially he seems to be doing the right thing, ensuring that Lady M is treated with respect as a hostage, not allowing his men to rampage and pillage, going and listening to the chiefs to get their opinions.
Along the way, he and Lady M mutually seduce each other. Lady M definitely doesn’t love him— she is in all aspects a queen here, and is trying to figure out how best to reclaim her power without England stomping on Scotland further. In her eyes, that means an alliance with England, and because she loathes Malcolm, that means Siward is the best prospect.
Hence the conflict. Lady M and Siward both want peace for Scotland, but both understand peace very different. And that brings us to the halfway point of the play, when Siward screws Lady M over and then is shocked when she gets revenge.
*Lady M and Siward have an affair*
LADY M: You know, there could be peace between Scotland and England, an alliance forged by marriage….
SIWARD: You’re right! So listen, I’m going to bring you in front of all the chieftains because I had the best idea.
LADY M: *smiles* I can’t wait to hear it.
SIWARD: Okay, now that you’re in front of all the chieftains and can’t refuse, here’s my idea. You and Malcolm are going to marry!
Lady M: …
Lady M: Okay, right. Time to kill everyone.
I just— dude. Dude. You set her up in front of her people, tricked her into agreeing to marry a man she despises, and then you get indignant when she gets revenge and escapes?
God save me from honorable men.