You might be noticing a trend here: I've spent most of my time watching tape on CBs and WRs. There's a good reason for that, and it's not so much about 2014 as it is 2015 and beyond.
Take the CB position for example. It's pretty much newly-minted Tramaine Brock, newly-arrested Chris Culliver, special-teamer Darryl Morris, and then three vet-minimum type guys who might or might not make it out of camp: Chris Cook, Perrish Cox, Eric Wright.
Someone could easily come in and take the starting job in 2014, and 2015 certainly looks like there will be gaping holes at the position. The front-office can't hedge their bets that *hopefully* someone emerges as a top player from this presently rag-tag group. If that last phrase upsets you, remember that the NFL is a "what have you done for me lately" league, and those vets previously mentioned haven't done much in years.
Hence we march onward, today focusing on Darqueze Dennard, formerly of Michigan State. Chances are you've seen his name on mock drafts, as he's long been thought of as worthy of top-level consideration. Still others are not sold on Dennard, and I'll try to help explain why.
Positives:
A very physical corner who keeps tabs on his man all the way down the field. He's not afraid to tackle, either, often throwing his weight into the fray. You'll see him knife-in from the edge on blitzes at times, as well.
Dennard's technique in pedal-turn-run is probably the best of the upper echelon crop, and when he can keep his eyes back toward the line of scrimmage, he plays as though he's the WR with the ball in the air, routinely getting his hands on the ball in one way, shape, or form.
Negatives:
The physicality will get Dennard into trouble at times, as he uses his hands to track the receiver while he looks back for the football. Often times these are harmless no-calls, positioning himself for the INT (aka: playing the ball, which is legal). Still, he does get grabby and uses the arm-bar enough that he'll draw some DPI calls.
He also needs to work on closing on throws in front of him. I feel like deja vu every time I write that because it's true of most of these college corners. When he reads the play all the way, he's fine, but if he's watching his man and not the QB, a throw can sneak in before he can close ground to break things up or make an instant tackle.
Lastly, though he's willing to mix it up in the run game, his tackling could stand some refinement. He's more of a cut tackler, though generally effective.
Conclusion:
Grabby at times, physical down the field, always trying to make a play...that could get a guy in trouble. Oh, wait, that's exactly what Richard Sherman (and most of Seattle's secondary) does. You can really see signs of a blanket CB in his game, and as the Seahawks have shown, the refs aren't going to call everything. They catch on to how guys play and have to swallow their flags and let 'em play at some point.
I see some things that could be coached-up in Dennard's game in order to reduce the penalties and help him be more effective vs. the run and in zone coverage, but what he has in natural ability and instincts can't be taught. I would not hesitate to take him in the top-15 of this draft, were I so positioned.