Actually, I have not heard Rice speak at length. "Diplomats" rarely make interesting speeches. I never listened to George Shultz make a speak on diplomacy either. Or Edmund S. Muskie, not I. I think it will be difficult to find a Republican willing to stand up to the Clinton machine.
I forgot to mention: Al Haig was one of the few secretaries of state whose speeches were easy to listen to and understandable. And even he made gaffes.
You are in for a big surprise; beyond a doubt, she's one of the most mesmerizing speakers I've ever heard.