I was more impressed with Bosa's 2014 season than his 2015 season film. I believe it was the Michigan State game, he was causing such problems they had THREE people blocking him. It was something else. His 2015 film still looked good though. I've seen plays where when he doesn't completely beat an O-Lineman with a move on a run play, he'll overpower his blocker and clog up a running lane. Like with Jack, the more I see of Bosa, the more I'm liking as well.
As for Gregory, I'm not sure his tape was THAT much better. I don't think anyone would deny how good Gregory was in college, what people questioned is if he could translate well into a DE in the NFL; especially a 4-3 DE.