Davis is a playmaker, hard-hitter, and gambler. But he's also the guy you want to throw at, because right now, for every big play he makes, he's likely to make an ill-advised gamble or a rookie mental mistake. He's more likely to bite on fakes.
Smith on the other hand, due mostly to his size, has the potential to be a shutdown corner. He's got plenty of confidence, but he's regularly a step behind. His tackling definitely needs work.
Basically, in training camp, it was evident Vontae had a LOT to work on. Concentration, technique, etc. I think he realized that, hunkered down, and has improved greatly.
Smith looked amazing in the beginning (pre-season). I think this got to his head a bit. He's regularly tweeting and enjoying the night life at a time when it would help to have his nose in the books. He's been inches from being embarrassed in several games this year, and IMHO it's been luck those throws have gone incomplete. I think initially from his play in pre-season he generated some avoidance on the part of opposing QBs..."oh no, a Nnamdi clone!" Now, I'm worried they're going to pick on him a bit more until he starts making some plays.
That all being said, I'm nitpicking because I want them both to perform this year. For rookies, they've done fantastically, they've got a mountain of potential, and I'm excited about their future development.