I saw King Charles III in London (where it won the Olivier Award) and I found it quite excellent. BUT, it is written and performed as a Shakespeare History Play - so, it's in verse and highly stylilzed. It does not require intimate knowledge of the current Royal Family - as the Royal Family in the play are characters - not the real people. But, some basic knowledge of Charles, Diana, Camilla, William, Kate and Harry is helpful. It is definitely not for everyone. But, much of the primary cast is the London cast. Of those: Tim Pigott-Smith as Charles was very memorable and Lydia Wilson's Kate was terrific. .