I'm high on Chubb and Davenport, because the league has tended to counter athletic QB's and modern packages by bull rushing their DE's or 3-4 OLB's on base downs, and sometimes on 3rd down, without giving them much freedom to deviate from their path/gap. Recent DE's who have outperformed their draft positions (be it character or other) include guys like Justin Houston, Chandler Jones, Frank Clark, Danielle Hunter, Cameron Jordan, DeMarcus Lawrence, Yannick Ngakoue, and Emmanuel Ogbah. These are some of the longest DE's/3-4 OLB's in the league, with the exception of Lawrence (still long) and Ngakoue, and they all win with their hands, which allows them to produce significant plays on base downs. They don't need to deviate from their path (or even the threat of it) to win against OT's. Some of the other top guys (most drafted at appropriate value) have shorter arms but combine exceptional strength, athleticism, and skill - thinking Mack, Bosa, Griffen, Kerrigan, and Ingram, etc. If you're not one of these guys, you have to be a Clay Matthews, Von Miller or Bud Dupree, play LB about as well as you rush the passer.
Chubb and Davenport fit these models. Chubb reminds me of Jared Allen and Joey Bosa, and Davenport reminds me of Aldon Smith and Chandler Jones, but I also see the Jason Taylor comp. I think you're exactly right about his effort and violence making him an excellent run defender in the NFL. He looks like a guy who is just scratching the surface of what he can be, and he's already very good. Outside of Mayfield (don't think Chubb is going?), Davenport is my top player at the Senior Bowl, and I expect that most people will have him in the top 10 by the end of SB weekend.