If you want to look at their high school accomplishments/stats.
LB
I like one of them very much and the other is a riddle harder for me to solve than Advanced Sudoku.
Tariq Allen LB 6-1 235 Irving, TX
The critique of Tariq (rhymes!) appears to be that he can't man up on a slot receiver or cover Joe McKnight on a fly pattern. Since that brilliant analysis extends to 97% of the LBs on the planet, let's move beyond the world of Nintendo and pretend we'll occasionally play against offenses run by men. This guy is a striker, he has real LB instincts, quality fundamentals, and he does a beatiful job of attacking with evil intent. Most impressively, he has the patience to play the run correctly (inside-out) and never overruns a play. There's nothing harder to teach a LB than to settle and diagnose rather than sprint around like an asshole biting on every play fake. Tariq gets it. This is refreshing to see in a high school senior when our LBs have struggled with this concept for well over a decade. This is an intelligent, athletic, mean-ass football player who is Mr Fundamental. You see an angry dude named Tariq and fundamentally sound and heady don't leap to mind as descriptors, but that's exactly what he is.
Patrick Nkwopara LB 5-9 205 Grand Prairie, TX
When I 'ship a 5-9 205 LB prospect that can't play safety, I want to see a running back's speed and a politician's change of direction. What I see is a super-productive District Defensive MVP whose physical attributes are nearly maxed out. If it's true that Muschamp was the decider on this, I am inclined to hold my opinion, but my lying eyes persuade me otherwise. The Scout site describes him as "rangy" which somewhat amused me. It's possible to like a player a lot, but not see him as our best option. That's my feeling for Nkwopara. There were a couple of better speed LBs in 2009 and there are a half dozen in 2010. He should be a demon on special teams though.
DB
Generally, when recruiting gurus talk about someone having the ability to play corner and safety, your radar should go up. It's like the dreaded combo guard in basketball. Generally, that means that they are athletic enough for safety and tough enough for corner; but not tough enough for safety and not athletic enough for corner. I think these three may prove to be the exception. Very difficult group to evaluate given that we don't know the long term impact of Vaccaro and Barnett's knee surgeries and we never got to see much of their senior seasons. I do like that none of them suffer from Beasley-itis. They're all willing to mix it up and that's important when playing against spread offenses where tackling is at such a premium. We need two of them to pan at CB for us - there's a log jam at safety.
Marcus Davis DB 6-0 190 League City, TX
Dude is active, likes to hit, and has the size and speed you want at CB or S. The question is whether he has the quicks for CB. There's no question that we'll start him off at CB and see what he's about, but he's certainly physical enough to play safety for us. This is a good player whose primary misfortune is to go against a lot of elite players in the All-Star practices in drills that give the offensive man a significant advantage, thus resulting in various gurus breathlessly reporting "his struggles." Really? A guy struggles when he's one-on-one in man coverage with an entire green field behind him and no safety help. Shocking. Within the construct of a real defense, 11 on 11 - and with the ability to mix up coverages - Davis should be a player for us somewhere.
Kenny Vaccaro DB 6-0 190 Early, TX
I find the largest range of opinion on Kenny of any recruit we've taken. In fact, I've read and heard opinions from people I respect all but consigning him to special teams. The knock on Kenny is his inconsistency, but when you understand that he lost his father in high school, transferred from Brownwood to small school Early where they played him at LB (and he dominated pre-injury), and had a knee injury that ended his senior year, things make more sense. This is a guy who needs our family atmosphere and when you view his junior film you understand why Texas stuck by him. He demonstrates ball skills, speed, physical play, and a constant willingness to mix it up and deliver blows. I like him as a safety though he has very reasonable coverage ability. You also need to take a hard look at his body: low body fat, big frame, lean, high school powerlifter. This is a guy who can carry 205 and not lose a step. If Kenny can get some stability in his life and a good knee rehab, he may be one of the most underrated recruits of this class. I'd shirt him for now (previous coverage).
Eryon Barnett DB 6-2 185 Euless, TX
Eryon lost his senior season to a knee injury, but the national interest in this kid was understandable. Legit 6-2 corners with long arms who will strike you don't grow on trees. He put on 15 pounds from his junior to senior year and we can expect another quality 15 at Texas. He's a bit of an X factor given that he was robbed of most of his senior season, but a reasonable rehab should make him a guy we covet as a press corner who can alter routes, disrupt timing, and punish receivers in the flat. Everybody is always looking for the next Mike Haynes...this is an obvious take, a guy you have to take.