Ok, here's the information from The War Room. They have him rated as the #5 DT, while Pompei rates him as the # 3, but that shouldn't make a difference, since everyone have him as one of the three DT, that's just a step behind Robertson and Kennedy (Joseph, Sullivan & Williams).
Kevin Williams
PROJECTION: Round 1, Pick 15
School: Oklahoma St.
Position: DT
Overall: 8.4
NFL Comparison: Bryant Young, 49ers
Positional rankings:
-initial quickness: 2
-pass rush: 3
-pursuit/tackling: 1
-run/pass recognition: 9
-versus the run: 11
War Room analysis
Vs. the run: Is durable and experienced. Is quick, explosive, powerful and athletic. Is a one-gap penetrator with improved size. Still lacks great bulk. Plays too high, losing power, at times. Must use hands better to disengage blockers. Finds the ball quickly once through the line, and is athletic enough to change directions and chase it. Can be extremely disruptive. Grade: 8.3.
Pass rush: Is an athletic, quick and explosive pass rusher. Changes directions quickly in the backfield. Shows above-average burst to the quarterback. Is a powerful tackler with good pop. Has some big-play flair. However, lacks power-rush moves. Must use hands better to disengage blockers. Grade: 8.0.
Initial quickness: Shows good initial burst off the snap. Is at his best in one-gap situations. Gets consistent penetration because of anticipation and quick first step. Grade: 8.4.
Run/pass recognition: Has terrific diagnostic skills. Locates the ball quickly once through the line. Changes directions and pursues better than most defensive tackles. Grade: 8.3.
Pursuit/tackling: Has excellent chase ability; has the speed and agility of a defensive end. Makes a lot of plays on the move, and changes directions quickly. Is a solid tackler with good short-area power. Grade: 8.2.
Bottom line: Williams was a durable, productive starter for four seasons at Oklahoma State. He is a hustling, athletic tackle who improved his draft value with a strong senior season -- he also added nearly 20 pounds in the last year but maintained his agility and explosiveness. Williams could play a one-gap defensive tackle position or move to end -- or rotate between both spots.
Dan Pompei analysis
Four-year starter upped his stock as a senior. Was very impressive at the Senior Bowl and had a fantastic Combine. Shows all the ideal tools for the position. Has size, strength, athleticism and quickness. Diagnoses plays and gets to the ball. Is instinctive. Rushes the passer and plays the run well. Gets hands up and tips passes. Uses arms well. Jolts blockers. Penetrates consistently. Is versatile enough to play end.
Pompei's DT ranking: No. 3.