Davis best asset without a doubt (well, at least I have no doubt about it) is his eyes. He's looking for an opening, or a seam, or even a little crack to wiggle through all of the time. How many times do you see a back run right up into the backside of his blockers? What's he looking at when he does that?
DD's not the quickest guy out there. He's certainly not the fastest guy out there. He's shifty and if you show him some daylight he's going to get good yardage. (4-5+) every single time he has an opening to pop through. You can't put a price on that. I'd love for him to have breakaway speed or that "Jedi Mind Trick" thing Sanders used to be able to do but you can make a very good career out of being able to simply spot a hole and get something consistently.
Fitz makes bad decisions. That's not going to change.