The stricter practice and meeting time limits in college definitely make a difference. When Mike Sherman moved from the Texans to A&M he talked about that being the biggest adjustment that he had to make. After his first season he consulted with one of the top Texas high school spread coaches (I think it was Chad Morris, then of Lake Travis, later Clemson (where he recruited Watson), and now SMU) about how to make his pro system easier to communicate and digest for the college game.
Here's a story about what went into the Texans' pick of Watson. Nothing groundbreaking, although I was mildly surprised to read, given The deBrockle, that O'Brien wasn't at the team's dinner with Watson during his pre-draft visit to Houston. He may have spent the rest of the day with him, though.