I thought Atlas Shrugged characters were too black and white myself, but The Fountainhead proved to have more diverse characters. Dominique and Gail Wynand were much less perfect that Dagny and Francisco. Howard Roark even slipped once in his ideology, and he was the "hero."
Aye, that was my objection to it as well, and the writing style is equally stiff. It is also one of the reasons I much prefer Heinlein to Rand as well; Heinlein created much better characters. I'd take Lazarus Long (from "Time Enough For Love") over any of the Randian characters, for example.