We saw Othello Friday evening. I had prepared in advance by reading the Arden Shakespeare book which introduces the play and provides the script. The plot line is more direct than some of the Shakespeare plays we have seen and easy enough to follow even if you haven't read the play in advance.
The Arden editor observed that the lead role is contested between the characters of Iago, the eternally scheming trickster, and Othello, who descends from nobility to duped, banal evil. The Iago role is a joy - a clever, manipulative, bad guy who pulls the strings of every other character.
Othello seems to me more difficult: the actor needs to project enormous authority and charisma at the start of the play, as befits a senior, experienced military leader. As the play progresses, Othello needs to convincingly 'buy' Iago's web of deception and internalise a set of beliefs which make the 'honour-killing' of his wife, Desdemona, convincing to the audience.
The problem with this performance was that Othello was played more as a senior bank manager than any of the above, which kind of left a hole in the proceedings. Everyone else was pretty good, though.