As a Caps' fan, I was excited when Chara came on board last year. Pretty cool to see one of the legends suit up for your team.
On the ice, Chara was perfectly serviceable through early/middle part of the season. I thought that his play noticeably declined as the season went along. IMO, he was a liability in the playoffs.
My preference was that Caps do not bring him back. It's not even so much about his play as it is about the fact that you cannot make him a healthy scratch. If Chara wants to play in every game of the season, he will play, even if it's to the detriment of the team. I think that's why Boston chose not to keep him around.