He sucks. Some may agree some might not, but I can't think of any attributes he possesses that classify him as even average at his position.
His coverage skills are mediocre, he's a shaky tackler, he can't get off a block to save his life, he's slow and not much of an athlete that he was coming out of Ohio State, he's constantly late getting the calls in. When the ball is snapped half the time he's still looking behind him trying to get everyone into position.
He does need to be replaced, IMO. But by who? There aren't really any good ILB's available through FA and drafting an ILB and putting him in right away is a crap shoot unless we take one in the first or second round which I can't see us going. Even if we did, we're still rolling the dice. But at the same time, I don't think it would be any worse than what Hawk currently brings to the table. As long as the guy is an athlete and a sure wrap up tackler, I'll take him over Hawk