Here is a thread on Sweat from a ND site.
http://www.irishenvy.com/forums/showthread.php?t=20662
They seem pretty confident, which worries me since I think Sweat is the most instinctual linebacker we're going after this year(with the physical presence and athletic upside to accompany it).
I think Sweat, out of all the linebackers we're going after, would be the one most capable of making an immediate impact. He just understands what's going on at all times, knows how to control his body and avoid getting caught up in traffic, and finishing the play with authority.