I don't think Gagnon is a player Devils should be looking to sign.
He is, as others have pointed out, as tough as they come. He will protect teammates and not allow cheap shots, usually. He jumped Cole Shudra and then forced Valdix into the ice and fought Fitzgerald within about 20 seconds after Shudra threw a high hit on Lee in a 5-0 game. He is very tough, he will protect his team but he was exceptionally inconsistent when it came to playing the tough guy role. I don't know whether it's a case of he knows most of the guys on other teams or was told not to fight or what but I'd say in at least 7 cheap shots against Panthers out of 10, Gagnon did nothing. The other 3 times, probably 2 of them Gagnon would have words or see if the other guy wanted to fight, and the final 1, he dropped the gloves. Now, I don't want a tough guy who'll drop the gloves or lose his head every game but there were many occasions where you'd sit and think 'Where's Gagnon?'.
Playing skill wise, he was decent. Not a liability but not a leading defenceman who you'd want to put too much responsibility onto. He had moments where he was brilliant and used his body well, and other moments where he looked confused and out of place. He's a big, heavy body and when he used it, it paid off but he did not use it enough. Skating wise, once he gets going he's pretty quick and being as big as he is it'd be like walking in front of a bus getting in his way. However, he never seemed the most durable player, he'd exert a lot of energy on a breakout, coast to coast type play, but struggle to get back into position. Quite sluggish at times and never moved exceptionally well. He's a young guy in the grand scheme of things so personally I feel it's the mental aspects of his game which hold him back most. Does a lot of talking to opposition tough guys so it makes you wonder where his focus is.
I don't think we saw the best of him in Nottingham but I'm confident he could be upgraded upon. I did like him and enjoy watching him in Nottingham, and although he was frustrating to watch too at times, I'm not massively bothered that we probably won't see him back in Nottingham this season.