Some comments from reddit. Don't take them for granted, but whatever... :|
"Matteau doesn't do any of that, and he takes a lot of horrible penalties.. so at least you won't be lied to. You'll hate him right off the bat, I assumed he'd be a career AHLer."
"I think every Devils fan will be absolutely delighted by this trade. Matteau has failed to make an impact at the NHL level at every opportunity and I never even dreamed of getting anything for him in a trade. I'll take Smith-Pelly's 55 points in 195 NHL games over Matteau's 5 points in 44 NHL games (and 1 in 20 this season) every single time."
"If you look at his performance during his draft year, you'll see two primary reasons he was drafted: his size and his reputation as a physical player (his last name helped him, too, I suppose). He was rushed into the NHL as an 18-year-old and then frequently scratched and left to rot in the press box. He lost waiver exemption some time ago, so he couldn't be sent to the AHL, either.
At the NHL level, he hasn't used his size or physicality at all. He is barely noticeable during most of his shifts -- unless he's taking a penalty or screwing up the forecheck. He is not defensively responsible, and at the same time, generates nothing offensively, so he was entirely useless in his time with us."