The problem with Kronwall is simple: the guy is asked to run the damn PP and HE isn't that type of guy period he should focus more on a shutdown role and be a physical force again. Where are his so impressive crushing open ice hits? You know the stuff Phaneuf and him are known for.
Guys who are clearly better:
Chara - *lol* at the notion that this guy is overrated he is an absolute monster and can do it all
B. Seabrook - this is one of the most underrated guys in the whole league, he rarely makes a mistake and gets the job done quietly
bold = elite, so yeah Kronwall is around ~ 12 good but not in the top group and for sure not elite
If Kronwall doesn't qualify as elite to you, then neither should Seabrook. Also Yandle is nowhere near as good as Kronwall in the defensive zone. And all I have to say about Chara is watch him closely next time you watch the B's. He's a good defenseman no doubt, but far from elite. He's not even the best all around defenseman on his team.