Jarvis Moss has the size to play both the 3-4, and the 4-3. He's listed at 6'6" and 250 pounds. Nobody was more heralded coming out of high school than was Moss. At Florida though, a number of injuries slowed him down, and he didn't truly excel until his senior year.
All I know is I saw one freak of an athlete when the Gators played the Buckeyes for the National Championship. Moss looked agressive, fast, and quick to the ball. At the Combine this year, scouts were unimpressed with his speed drills, making many wonder whether he would be able to play as a LB in the NFL, or would have to be a defensive end only.
It's not the speed that raises any eyebrow for me. He may be a smidge slower than some of the other LBs in the draft, but his instincts are good. His strength seems questionable for a defensive lineman though, at least based on Combine results. Moss only threw up 225 pounds on the bench press 16 times?!? Aaron Rosss, a CB out of Texas, did 17 reps. Maybe there's a mistake in reporting somewhere because that's flat out bizarre.
Moss may very well have a productive NFL career, but it probably won't start as a Steeler. I haven't seen a draft that has him going as high as #15. The Steelers are in desperate need of a defensive end like Moss though, especially if they're interested in switching over to the 4-3 under new head coach and defensive mastermind, Mike Tomlin.