I think we only used Denethor in one game, but it was certainly interesting! If I remember correctly, he had a tendency to switch sides during the game.
While the sculpt itself is relatively simple, the face does have a number of nice details. Perhaps because GW was trying to get an actual likeness...
Many of the colors of the cloak were also used on the face, hoping to give it more of an aged, care worn look. That of a custodian who has been in place far too long!
He's also here: