I don't know that Hader is much different than last year. The difference is that he's closing more games which is a higher pressure situation. Last year Hader only "finished" 14 games all year. He has already finished 14 this year. Losing Knebel has put him in more tough situations.
Statisically, his WHIP is down, he's walking fewer guys and is striking out more guys. Last year he had 12 saves. This year he has 11 already. Yes, the HRs are a problem but I don't think he's really all that much worse.