There's a really interesting, recently released HBO documentary called "The Defiant Ones"[1] which is about the story of Interscope Records, Jimmy Iovine and Dr. Dre. Trent Reznor is interviewed in it, because he has worked with Jimmy Iovine for quite some time. Iovine, Dre and Reznor all come across as very smart, humble and incredibly hard working individuals.
Here's a clip regarding Nine Inch Nails and Iovine: https://www.youtube.com/watch?v=HPJZdtyXAVo
The whole four episodes are well worth watching.