Sheen should return as Blair on The Crown.
Peter Morgan's The Queen captures many of the nuance of his work as a whole, and even though The Crown is somewhat much better in so many ways (mostly thanks to the amount of time he has to flesh out the characters), this was a still nice look into a tragic and important moment in the monarchy's history. Helen Mirren embraces The Queen, pretty much becoming her, and it's among the best out of the film.
The script unfortunately finds itself struggling to balance everything into a compelling way, though it still has some great moments and exchange between the two leads.
All in all, a nice little story that worth a watch for the great acting alone.