http://uproxx.com/sports/2015/08/josh-rosen-ucla-qb-profile/
Rosen and Heaps are actually opposite in a lot of ways. Heaps was groomed to be a college QB from the time he was in little league, and I believe his dad had sent him to numerous QB camps. He was one of the most polished high school QBs, as a result.
Rosen, on the other hand, was being groomed to be a tennis star, and he really got into football only when he got to high school. However, Rosen admits he doesn't love football and sees it as a means of achieving other goals in life. He grew up wanting to go to an Ivy League school and work on Wall Street (I think his HS GPA was well over a 4.0), but he decided playing big time football opened more doors.
Rosen may indeed be a bust as a result of his lack of love for the game and/or arrogance, but he is quite a bit different from Heaps. I think he's a lot smarter than Heaps and less likely to get rattled or lose his confidence the way Heaps did. But he may have to deal with a divided locker room like Heaps did, as many of the players were pulling for Neuheisel to win the job.
Here's an interesting article on him that explains a lot of this.