I didn't watch DT at Alabama but I believe he had north of 50 sacks in college and won the Butkus award. I do know he went to 9 Pro Bowls and had 20 sacks his 2nd year.
This I don't see Howard as Derrick Thomas out of Alabama at all. His game is not nearly as explosive IMO. His game is not strickly pressure through the rush. I think he's much more simular to a poor mans Johnson.
However, I do agree with you that he is closer to a 43 OLB, such as Thomas or Johnson, then a 34 LB such as Porter. At least, right now.