Pros: Displays relentless pursuit from snap to whistle - though he's not terribly fast in short spaces, the clichéd term "non-stop motor" applies here. Great turn around the tackle when rushing the passer, and he's got the ability to turn out of the rush to go after the run - he's not just a one-directional player. Excellent sense of run direction at the line; he doesn't just blindly pursue. Instead, he'll stop and assess and redirect to make the tackle.
Knows how get aggressive with his hands at the line to get around blockers, and he presents a very impressive hand-strike at the point of attack. No matter how hard he's going against a blocker, he always keeps his eye on the ballcarrier. Potentially dominant as a wide five-tech pass rusher - he wouldn't have to engage a tackle straight on.
Cons: Watt runs around with a lot of energy on the field, but the lack of straight line speed for his size (6-foot-6, 292 pounds) shows up when he just misses tackles and winds up diving for ballcarriers that aren't there. Has the power and pop to split double-teams, but can just as easily be re-directed out of the play by power tackles. Gets by with quite a few ankle tackles - he'll have to work on wrapping up at the NFL level. Basic technique flaws in certain instances, but these are things that can be worked on at the NFL level. The basic structure is there.
What he brings to the team: Players like Watt are in a "right place/right time" scenario with the upswing in hybrid fronts (3-4 to 4-3 and back) and the increased need for defensive linemen who can alternate between penetrating past guards at defensive tackle and stopping the run at five-tech end. Half a decade ago, Watt may have been relegated to a straight three-tech position that really didn't fit him (think Adam Carriker with the Rams), but he's now got a lot more options at his disposal.
Watt could make a big difference to any line needing a run-stopping end opposite a pure speed-rusher - a player who could also operate inside in nickel sets and other obvious passing downs. One of the reasons you see so many ends and tackles at the top of anyone's draft board lately is that it's a rare era in which talent and scheme need have exploded at the same time. That's great news for Watt and many of his contemporaries.
Is it the right pick? For the new Wade Phillips defense in Houston, Watt will play the role of Marcus Spears — the end who can penetrate, but who also soaks up blockers. It's very curious that the Texans didn't address their secondary in the first round, but perhaps they have their eyes on a later pick.